In these days, my brother discovered an online flash game, called “Birra Moretti Calcio”.
It is sponsored by an italian beer. It’s an amazing game; you can be a footballer or a team manager.
If you decide to be a football player, you have to train your skills like tackling, shooting and so on, playing some simple little games.
I can chat with other people and deal your transfer in another squad. There are many leagues, like hattrick (another online soccer game), but the awesome thing is that all the “actors” (players and managers) are humans!
Simple, addictive, playable with any browser; I tried using Internet Explorer, Mozilla Firefox and Mac OS X Safari.

Cheers,
Marco