Today is a great day for jailbreakers, in case you haven't noticed. FolderEnhancer, the great tweak that brings dozens of new features to iOS' folders, has been updated to include support for iOS 4.1. It's available in Cydia at $1.99, but if you're a previous CategoriesSB customer you can get the app at $0.99 until the end of October.
With FolderEnhancer you can open folders in fullscreen above the dock (other apps on the Springboard will be hidden below a folder); create folders in folders; open folders faster with the app's fluid animations; place up to 320 apps in a folder with pagination (16 apps in 20 pages); have MultiIconMover and Iconoclasm compatibility; hide a folder's name and choose a custom background. A future update will include vertical and paged scrolling.
FolderEnhancer is no doubt the best tweak for folders, another must-have for jailbreakers. Take a look at the demo video below.