If you're suffering from app overload, this independent app store doubles as a housekeeper. Find new apps, update those you already have, or mark several for removal in your desktop web browser and AppBrain will do your bidding.
WIRED Track price drops. Set background wallpaper from your desktop. Move apps to an SD card to free up memory (as long as the app involved supports it).
TIRED Android 2.2 includes many of the same features. Not as pretty as Android Market.