We are expecting the new iOS 4 for iPad that has many new features, including App folders which help you organize your apps into folders and quickly access your apps.
How to Create your own Folders
Make sure your iPad is running iOS 4.0 or newer.
1. Touch and hold the wanted application icon on the screen until it all the apps start shaking.
2. Simply drag this app icon onto another app which you want to put in a folder
3. A new folder is automatically created.
If you constantly work with many different apps on your Apple devices, this feature is very helpful for you.
About the Folders limit
By default, you can put only 12 apps in each folders. You can use jailbreak app to remove 12 item Folder limit.
Others tips
Taking all applications out of the folder to remove a folder.
In order to rename Folders, going into the folder and holding down your finger on an app key.
You can't move a folder inside another folder.