I would start by looking at the camera review sites. The ones I'm listing has fairly extensive reviews:
http://www.dpreview.com/
http://www.steves-digicams.com/
http://www.dcresource.com/
The more megapixels isn't always a good indicator. The size of the chip sensor is a better indicator of how good the resolution is going to be. You could have a cheap 5mp camera that doesn't output better resolution than a 3.2mp good camera.
I'd stick with the known brands: Canon, Nikon, Minolta, Fuji, Kodak. They've been in the business long enough and they know how to make good cameras. Sony is a big player too, however I don't like their memory stick so I stay away from them.
Optical zoom is the only way to go. I find most point-and-shoot only range around 3-4x optical, which I find isn't enough. There are several ultra-zoom cameras out there right now, most in the 3-4mp range with 7-12x optical zoom. They're great if you like zooming in, however the downside is that the camera will be bulkier and heavier than a lot of the point-n-shoots. Also to consider with the longer zoom, the shakiness that could occur because with longer zoom the camera needs more stability in focusing.
It all depends on your needs. I myself have a 2mp that I'd like to upgrade to right now, so I'm also looking thru the different cameras. Myself, I'm going for either the Canon PowerShot S1 IS with 10x opt zoom, the Panasonic DMC-FZ3 (12x), or the Minolta Dimage Z2 (10x). At this point, I'm leaning towards the Canon, not only because I trust Canons, but because it takes CF cards which can go up to 4GB in capacity - great for taking many many pictures - and it also takes regular AA batteries instead of proprietary batteries.
Good luck and have fun choosing.