This is how it ought to be - NASAimages.org is a huge new web collection of all sorts of NASA images and videos hosted not by NASA, but by the Internet Archive (which hosts a lot of other stuff too, some of it pretty strange). You can browse by categories (among other methods) and display up to 250 thumbnails per page. There are some cool features for browsing, searching, embedding, and for creating media groups and presentations. I'm sure there are more features, but best of all is the easy access to zillions of NASA images.
There are already a huge number of images and videos but they apparently plan to expand to millions of photos and thousands of hours of video. Way cool!