Hosting Family Pictures Solution

My family has an addiction of taking pictures… Terabytes worth of pictures…

So I will assume I have a user base of about 30 families (I will assume 1 person/household). Most are located is geographically diverse locations. There is maybe 5TB worth of pictures that need to be in a single location accessible by everyone. We do not mind having some start up cost ($1,000-$2,000), but month to month cost I would like to keep low.

What would be the best way to share that many pictures, in a user friendly way.

I do not want to do an FTP based folder solution. Unless needed. They want to preview pictures on a site before downloading and such. Is this an impossible task?