Picasa is a free piece of software which allows you to store, edit, organize, and share digital photos. I just started experimenting with it and am finding it very easy to use. Picasa has organized my photos into folders, yet I am able to scroll through the entire collection from beginning to end and see every picture without having to open and close folders.
I opened Picasa for the first time this evening. It immediately asked to scan my hard drive copied every one of them into Picasa, all categorized into folders.
That’s really all I know right now, but what I do know, I learned in about 10 minutes. So, if you are looking for a way to organize your digital pictures, check it out.