Ideally I want a camera no bigger than the Casio Exilim EX-S3, (89.5 x 57 x 11.7 mm to be exact). It's how thick the camera is that is important so it fits in your pocket easily. I want one with more than 3.2 Mega Pixels.
I'm not bothered about zoom, because it's always rubbish on digital cameras.
Also it would be good if you could record video with sound depending on the amount of free memory not just a set 30 seconds.