This one is very interesting and comes from Christopher Blizzard who has been developing the site as a personal project alongside his day job as an open source evangelist at Mozilla Corporation.
whoisi.com is a radically new concept and for that reason it can only be explained by reference to other concepts. The site is a very powerful alternative to services provided by the likes of Facebook and similar social networks such as following people’s online activities. The wonderful thing is that it does not require you to register or be a member, so it has no aspirations to spread itself through mandatory registration to provide the service.
The service is also a kind of Wikipedia for people. Anyone can add people, edit their aliases and add URLs related to them. Thus, you quickly get a very broad amount of information about the person and his/her activities.
There are a few more cool features that I am not going to talk about but overall it looks like it could be a new paradigm for these kinds of services. For more references take a look at the about page, Chris’s blog or his blog entries that announce and talk about the first days of the service.
If you want to follow me on whoisi.com use this link.
2600 is a nice round number.
@Christopher: Yes, I was pleasantly surprised to get such a nice round number as well. But it is not so round in base-16 (A28) so it must be a figment of our anthropocentric decimal system. I would take the number 1 over 2600 any day.