Oh My Gentlemen is definitely the largest clan in the game, ergo your best chance of finding a game 
We use a program called ventrilo (or just vent) to communicate, and we use the public lagwars server:
Oxygen.typefrag.com
Port: 50216
Our clan thread is in the Demigod general section. All you have to do is add OMG_ to the beginning of your name to join. (you can do this by going to my account at the top of the page and editing your nickname, but note: this changes how you log in, so remember to type in OMG_ before your username when logging in)
Should you join, you'll find a bunch of cool people who are good at the game, and you'll learn a lot, no matter how good you are.
We do cool stuff from time to time like all rook games, or yeti wars, or all DA games.
I look forward to seeing you on vent sometime soon if you join 