I really like www.shutterfly.com
because if you download their tool you can set up your photos to all download and go to bed. It'll keep working on it all night. Another plus is that you don't have to sign up in order to view
photos - whereas several others force you to do this. And you get your own website that you can give to people like www.BelizeItPlease.shutterfly.com
(not really mine so it won't work, but you get the idea).
One word of warning, it's actually a photo ordering site, so once you upload your pictures in hi-rez, it'll only display low-rez versions, which is GREAT for sharing because they show up fast, even for those on dial-up, but not so great if someone wants to right click and use it for their own uses because there's not enough there for anything larger than wallet size.