Online graphics/art program - create doodles, posters, cards or make a story - lots of fun.
Also allows pupils and teacher to create online movies - all graphics provided.

Free account allows a save of work done.

Maths/logic based games + try Powerlines if you dare !!

Maths based games + other non-maths games

Graffiti creator

Maths games (download - only) useful for teacher

Nice collection of games based around Nobel Prize and aspects. (some are difficult)