It would be nice to be able to make collections (groupings) of synths rather than just a favourites list. The concept of collections would also be useful as a starting page that you like. You may want to look at the work that Doug Kay has done recently to get spokenword.org off the ground. This is a great example of categories and collections. If Photosynth keeps going at the pace it is now going it will need something like this to navigate.