Well you get guilds in MMOs kinda like clans 
But going on to clans, there was a boom in console clans with Halo2 and Halo3. A lot of tournaments and stuff and loads of people wanting to get in on the action as the prizes were big and the sponsorship deals were not bad.
PC gaming still has many clans but with the likes of the new MW2 and the way the match making is done you don't really get to see clan servers or anything.
Still plenty of CS:S clans going.
Also in regards to the clans I know a lot of clans from experience just do private matches amongst them selfs or against select other clans.

But going on to clans, there was a boom in console clans with Halo2 and Halo3. A lot of tournaments and stuff and loads of people wanting to get in on the action as the prizes were big and the sponsorship deals were not bad.
PC gaming still has many clans but with the likes of the new MW2 and the way the match making is done you don't really get to see clan servers or anything.
Still plenty of CS:S clans going.
Also in regards to the clans I know a lot of clans from experience just do private matches amongst them selfs or against select other clans.

