The world of online gaming is one of the most interesting areas for internet and videogames industry and I think it's has a good future.
Playfish is a fast growing social games company with offices in London (headquarters), San Francisco, Tromso (Norway) Beijing (China). Social games are games designed to be played together with friends. The company creates games to play together over social and mobile platforms such as Facebook, MySpace, Google, Bebo, iPhone and Android.
Currently, the available open positions are in London (game artists, game developers, product managers, server side developers, system operations engineers), Tromso (web&graphic designers), Beijing (product managers): see here.