A few years ago, I spent some time playing Pente with a guy named Nathan via e-mail. I didn’t know him in real life, just from some message board (I don’t even remember which one anymore!). He had been playing for years and I was a newbie, so he kicked my ass every time, but it was fun . . . until he got a girlfriend and disappeared off the face of the 'net. That was the first and last time I ever played a game via e-mail.
I use a great program called Cyberboard. It is very easy to use and contains stuff like die-rollers and other things you need.
There are game boxes for lots of different games which you can find links to from the Cyberboard page or the Cyberboard Yahoo group. It is also quite easy to create your own game files if your favourite game doesn’t have files already.
I play two miniature wargames called Warzone and Chronopia (very similar to Warhammer but better) with Cyberboard. Of course it is not the same thing as playing a real game with nicely painted miniatures, it is a way to play against people on the other side of the world that I probably wont get the chance to meet IRL.