Tina,
Great to see, what you have done. If there could only be one person (or the vb.com team) that could unite the good features of your and the other (Avatars Category and Permission) hack. Because I would love to categorize not only smilies, but the images I upload as well.
An idea I had about this matter looks like this: we need to have just one "category" and one "metacategory" (last added, time and all other meta info about the other table) where, for example, all smilie groups have one cid incommon, all the avatar categorys have another and another feature would be good - to create subcategorys as we have subforums here. I understand that it's very hard, but you're not the only one arround, we could help. You're just on the right way

)