I have been a user of Bolt.com for about a year now.
It is geared to the age group of 15 to 20, but theyre are are a lot of people older than that who still use it.
It takes a long time to load, but once you get it going there are a lot of different features that you can use.
There is an e-mail/voicemail that is available once you sign up but it is optional.
There are Bolt Notes which is pretty much like e-mail only you cant save your messages.
There are surveys that you can take for fun and clubs rangeing from hundreds of different subjects.
There is even an online diary that you can use, you can keep it private or even make it public for the other users to read.
It has a friend finder where you fill in your intrests and it will find you other users with the same interests.
The list just goes on and on!!!
I love using it.