Anyone can join so.cl. It started as more of a learning site, but now it's become much more general. You don't have to do anything - if you go to the home page you will see that you can join it just through one of your other social networks - Facebook or Windows live are both OK, you just click on one of them, log in to your account and click on the so.cl app.

However, before you start you may want to check out all the implications of signing up. According to some social network users, there are privacy issues with soc.l - it seems that your searches may be visible to other users, for example, which you may not want. It's too early to say whether these problems will be resolved or whether the network is going to be a success, but you will want to be as well informed as possible before you join.