http://tribalwars.net/

Basicaly it is a MMOG (massively mutliplayer online game)

There is NO DOWNLOAD required, it is purely a web browser game.

You make your own village, gradualy build and strengthen it over time. Unlike games such as Cossacks and Age of Empires for example, you cant build a building in a matter of seconds. It Can range from 20 mins+ - days to build a building. Make friends and allys, or make enemies and war with other communities.

Its a nice game that you dont have to be logged in on all the time to play, doesnt even take much patiance as you can just play BF2 while waiting for your building to be built ;)

Cheers