Look at the
SD300.
Its smaller than the nikon and has better video it looks like (30fps v. 15, with sound, dunno if the nikon has that or not) but you lose 1 megapixel.
EDIT: Nevermind, the nikon does 30fps video as well, but make sure it does sound if thats important to you. Another thing that got me to go with the sd300 was speed, all the functions are quite fast, very little shutter lag. Again, dunno about the nikon.
4 or 5 megapixel is better than 3 obviously, but unless you're going to be printing 8x10s or bigger, a 3.2mp would do fine. You could even check out the sd200 and save some cash if needed. It has all the features of the sd300, but with 3mp instead of 4.
Check
Steves Digicams for reviews. You should be able to find anything you'd want to know about digital cameras, including sample pics and video.
As far as the SD card. I have a 512, and only one time did i run out of space (after taking some video). I'd say go with a high speed gig if you can swing it, but if not the 512 still fits like 240 pics or 4 minutes of video at the highest settings, which should be enough for everyday stuff.