Catagorize your favorites into diff. list of favorites

I just found out that I can put all of my different web sites into catagories and save them as the nameiwant.htm and then put the file in the directory i want and while explorer is on can open that file to see a list of the sites I like and then save it as a favorite instead of having one big long list I now have a short list of the catorgries that I made.