Through the software you can download other themes people have uploaded. I've downloaded a ton of them. Most are built for higher resolution (ie. Droid) or 2.0 phones so they sometimes don't function correctly or utilize widgets not available.
That being said, any of the themes created by Lemon run very well. I downloaded Hot Dock (my fav) and modified it to run well on the Moment with widgets i like. I will upload it in the next couple days. Once you learn how to modify themes, this software is awesome. The organization through use of springboards is super slick, It does have a learning curve tho, so be ready to get your hands dirty. Also, the home button doesn't function well on the Moment. Use the back arrow, it works better and won't cause SH2 to hang up.