Can You Give Some Suggestions About A Nice Social Site Where Our All Old Friends Can Form A Group To Keep In Touch?

The obvious answer would be Facebook, as it is designed around the concept of connecting people who already know each other.   You can easily create your own group, which all your friends can join too.

The only potential downside is that Facebook has millions of active members, so you may find yourself (or your group) receiving lots of unsolicited requests to join.

With yahoo messenger you can set up a private room for what you mentioned . You might be able to do that on this website also ? Click on groups on the homepage .

Friends really do drift apart after school. I couldn't keep in touch
with more than two of my school friends. One of the two has started a group in a site called www.tabup.com last month. We
are still gathering more people into it. It seems very informative as well. It could also work for you.

Dude you should totally go to www.IMVU.com I love it there!!

FaceBook, i have one do you??? It is awesome!!

Myfamily.com is a good sight for families or groups.  You can make it public or private.