During past week I hosted in my house a russian girl I didn’t know before. Why? She asked hospitality through CouchSurfing. I subscribed few months ago to CouchSurfing when I was looking for free hosting in Cyprus. In the meantime I also arranged to find hospitality in Paris. And of course I was very happy to host her (Anna is her name and here is her couchsurfing profile). Feel free to contact me if you pass near Trento, Italy (here is my CouchSurfing profile and it should be easy to find my email address around).
And as an example of how much information you leave behind yourself surfing the web, here you can see a map of places Anna has logged in from.
One evening she asked me to use Internet and I saw she was typing livejournal.com, and yes, she has a blog, though it is in Russian and I cannot understand it.
[CouchSurfing can be interesting also from a research point of view, see much below in the following text]

The Hospitality Club is a web site similar to Couchsurfing, although someone told me that the network is much bigger. And there is also Servas. However Servas was founded in 1949 and it is not a initiative born because of the new possibilities offered by the web. In fact they don’t exchange or publish information electronically but you have to ask for the list of a certain country (you want to go) to the local responsible and she will send it to you (by normal mail) the dead-tree list, then you can contact people offering hospitality, Everything is highly certified (the local responsible gives you a sort of Servas Identity Card that certifies you are a good person). Servas is much slower, personally it does not fit at all my requirements, since I often decide to go somewhere less than 20 days before. I tried to use it in US, Belize and Guatemala, always without success. Anyway if you want something slower but more sure and certified, Servas can be your choice.

Ok, so what is CouchSurfing (and HospitalityClub) interesting for?
From a global point of view, I really envision (or dream) a world where everyone is free to move everywhere (no more borders) and, as a first step, a place where everyone that want to travel the world and visit countries would be able to do it hosted by local people and at almost-zero cost. In this way, more and more people will come to know different people (white, black, green, red, muslims, hindis, old, young, …[add yours]…, just different people, the one we usually fear simply because we don’t know them, yes maybe we will able to just laugh when the media or the politicians try to push in our brain the idea that everyone else is a potential terrorist and we should fear her). And moving aroung the world will be possible for everyone and not just rich people as it is now. Surely it is very hard, for example, for people from African Univeristies to participates in International Conferences. And in general for people from not-rich countries to move around the world. That would produce a better world, I’m sure. A world of open houses, open cars, trains and transportation vehicles and …. of open minds.

And from a research point of view? Before hosting Anna, I asked myself questions such as “why should I host this girl I don’t know? Will she steal everything I have? Will my house be safe?” (you can complete with the classic paranoid bla bla questions). Why I’m happy to host someone she asks hospitality on the web and not someone that simply stops me on the road saying she has no place to sleep for this night and asking to take advantage of my roof and warm house? Why it is different?
Well, it is just the same question such as: Why I’m happy to buy from someone on ebay and not from someone that stops me on the road saying “i’ll ship you a wonderful guitar, just give me now 50 euros”?
Yes I’m going there ;-)
What makes people happy to use ebay for sending money to people they DON’T know is the fact that ebay gives “identity” to people, you can see the homepage of someone and you can see her history as a buyer and as a seller, and based on this information you can build and grow trust on her. Yes, Trust was the word I wanted to arrive to.
Basically Couchsurfing (and ebay) gives you additional informatiion based on which you can make decisions. In the real world, would you be happy to host a friend of your father? I think so, and why? Because you father trusts her and you trust your father. As simple as that. So technologies can be used to automate this process (the term “social software” is about this enabling power of ICTs). CouchSurfing collects and shows a lot of “social” information: who surfed with who, who certified who, who referenced who, …
This goes in the same direction as enabling hitchhiking or car pooling through some trust-facilitator ICTs mechanisms as was writing some time ago in Using social software for good: car pooling. Here the same arguments apply: I might be scared to open my car to a total stranger but, if my mobile tells me that she was already hitchhiked by 1000 other people and nothing bad happened, maybe I will be a little bit more open(minded). And the same if my mobile can tell me that this total stranger was picked up already 3 times by my friend Mary and she was happy with the lift and the conversation.
Actually, some months ago I asked to Couchsurfing founder Casey Fenton if I could get access to the data collected by CS and shown on the site for my research on Trust-aware decentralized recommender systems (PDF). But after a positive reply, I didn’t hear from him any news. The social data are very very interesting. I copy and paste from my email to him:

In general, if possible, i would like to also have this information
about an user:
#login name (or id if you want to anonimize the dataset).
#country (with longitude and latitute)
#State/Province
#City
#Spoken languages (with levels)
#gender
#age
#Occupation:
#Ethnicity:
#Interests:
#Music, Movies, Books: (particularly important since recommender
systems recommend items such as these ones!)
#Places I have visited: (important for developping a system that
recommends countries to be visited)
#Places I have lived:
#Places I want to go to:
#groups an user belongs to (again good for recommending which group
you might find interesting)
#Couch Available (yes/no/maybe)
#Preferred Gender of surfer:
#Max Surfers Per Night:
#how many photos did the user upload.
#some degree of activity of the user such as (total number of logins,
registration date, logins in the last 30 days, in the last 90 days, …
a more verbose output would be to log all the dates when an user login
in the system). this information can be useful to conduct studies
considering for example only active users.
# is the user verified? at which level?
# is the user vouched for? (of course i can derive this information
from previous logs)
# is the user ambassador?
# is the user certified? (this means “did he contribute financially?”)

I was also asking about detected attempts to spam the network, sybil attacks and the like:

one more question, if i may ;-)
what is your experience with SP_ A MM ?
there are people that send spiam (remove the “i”) messages to other users?
that write spiam profiles or link to spiam sites?
any fake profile (such as bill gates profile of john kerry profile…)?
any other abuse did you happen to see on couchsurfing?
i’m curious because the other side of social software systems is …
trying to abuse of them and use them for your “malicious” (depending
on your point of view) interests
(such as selling your book on amazon or attracting visitors to your
spiam page or …)

Actually I think I’m going to copy also the rest of my email to Casey, maybe you find something interesting in it as well:

Some suggestions:
#have you considered exporting personal and “friends” data of every
user in FOAF format (more info at
http://www.foaf-project.org/ or i can tell you something about it if
you like)?
#it would be great being able to “export” your profile to your blog.
the idea is that you provide some html an user can copy and paste in
her blog and this html “writes” some information from couchsurfing
about her profile such as username, place visited or location or
“Couchsurf in my house” or “surf my couch”, the couchsurgging logo and
of course all this information link to couchsurfing.com (it can be
good to spread the existence of your fantastic site!)
this is something similar to “flickr” (see for example caterina blog at
http://caterina.net/ and the photos exported from flickr on her blog
on the right), or allconsuming.net (on the right of my blog
http://moloko.itc.it/paoloblog/ you can see “books i’m reading”, they
are “written” by allconsuming using the html i copied there and pasted
it in my blog) and tribe.net. all these services allow you to show
your presence on these communities in your blog/site. [was i clear? if
not, sorry. i can try to be more clear, just let me know]
#there was something about geotagging user pages and let geo-aware
browser and application to see the map of users and browse it but the
main site about it geourl.org just went offline so i’m not sure it is
a meaningful project right now…
#you can even think some integration with flickr, every city can
become a “group photo set” on flickr or couchsurfing users can be
allowed to posts their photos on flickr…just an embryonic idea.
#you can show in the homepage the list of currently logged in users
(such as phpnuke/postnuke-powered portals often do). this could
possibly foster the sense of community.

Last words: Couchsurf the world!