Does anyone kno of any good PSP Games suppliers. US/English preffered thnaks

Does anyone know if the Xbox 360's are region locked? It doesn't say on the site I've just recently visited. Thanks.

I am a trader from the uk and i was wondering if anyone knew where i can get cheap PSP games (Any region Preffereed PAL or US) and cheap Xbox 360 games for resale (PAL Preferred) Thanks