Could someone give me some advice about digital cameras?

I'm looking for a compact digital camera with more than 6 megapixels, good optics, a reasonable optical zoom, a useful memory card and one that comes with the accessories needed to make life comfortable. Can you give me some ideas about what is available and where I can buy it?

There are probably a ton of cameras out there that fit your requirements. Just some things to consider:

1. Memory cards - Compact flash cards tends to be cheaper and more widely used although Secure Digital (SD) cards are smaller. Memory sitck (MS) and XD picture cards are limited to certain brands of cameras and may cost more then CF and SDs.

2. Accessories. What kind are important to you? If you're looking at dive and weatherproof casings, Olympus and Canon are good bets as they have them for many of their models. 3rd party underwater housings are available but tend to cost a lot.

3. Camera features. Do you need movie mode, movie with zoom, b/w, night shot/hight ISO etc etc?

A couple of (generic) recommendations are:

Panasonic Lumix DMC-LZ3 - 5 mpx, 6x zoom, image stabilizer, (and I think a leica lens)
Olympus SP-500 UZ - 6 mpx, 10x zoom
Canon PowerShot S3 IS - 6 mpx, 12x zoom, image stabilizer

go into a camera shop...ask questions , hold and play with them

Dpreview.com is a good web site to check out. On top of my head, you may want to consider Canon Rebel XT, Nikon D50...

http://www.steves-digicams.com/

i use the fuji finepix f11 , it's compact, six megapixels, 3x optical zoom and has good light sensitivity.

I'm a big fan of Minolta cameras. The quality is excellent and the cameras are user friendly.

http://www.bhphotovideo.com

you really can't beat their prices plus if it's available in the states, they have it. For what you're looking for, look for the Canon Powershots or the Nikon Coolpix cameras. Both excellent cameras with lots of options.

visit canon.com
you can find tons of information which you can use on other brands also