Appletiser (from Coca-Cola) have a timewasting game ready for you to play – and if you are lucky you can win a diamond. Based on a cross between Tetris and another desktop game (whose name I never got but I played a lot) you get a chance to play the game and then enter a prize draw for a diamond bracelet. You don’t actually have to play the game – of you start it and then click Quit it takes you to the entry form anyway.
Unlike many sites I’ve seen it does offer an obvious text only method of entering the competions, with out having to use the flash entry form. The text version gives a link which allows you just to email your entry (although it appears their tems and conditions don’t quite allow this)