1) If they are the same images, then it wouldn't be 10000 images, it would be 100 images, cached for each user to look at when they wanted. ASP.Net does quite a good job of maintaining the cache, and you can set a length of time that an item will remain in the cache, before any subsequent request has to go back to the database.

2) Did you look at the Beer House Sample kit that I think I mentioned earlier? Take a look at the DAL for the Forum module, it shows exactly how you can do it.

Gary