Last few years in Vegas I haven't taken many pictures. However, I remember the first year that I took a Digital Camera out there. There was so much to photograph. I think I went through 700 pictures in a week.

For a week long trip, I would definitely figure what you would need to get a few hundred pictures. If you aren't going to have your laptop with you or don't want to invest in a small storage device than you will want more cards to take up that capacity.

Incidentally, there are small devices that you can get on places like Herrington Catalog that are a small hard drive. They are portable and may run on batteries or you can plug it in in your hotel room. Some aren't much bigger than a portable cassette player or a little bigger than an IPOD. You plug your memory cards in there and can off load gigs of photos. Then, you plug it into your computer when you get home and save them to the computer later. I have even seen a few that will take your photos and burn them on a CD or DVD right there. Good idea to, at least, back up all your pictures while on the road. They are self contained and you don't need the larger laptop with you.