Some other quick options that don't require any programming knowledge:
- Smugmug.com is the Cadillac of photo sharing sites. The client can set up as many galleries as they want. If you buy the pro account, you can customize it completely and have it on your own domain. I'm starting to recommend it to artists who can't afford to pay me.
- WordPress is getting better and better, and will resize images and allow you to choose the size you want. You could build a whole website based on WordPress, leaving the blog function out and building pages only, and most people would never know.
- If it's a community based site, with a number of people involved, you could create a Flickr group and have people contribute photos to the group pool. Some of them may already have Flickr accounts. I'm trying this with a group that is trying to encourage participation and photo sharing among mostly older people - I figure it's the best chance I have of getting them to do it themselves.