iBrainstorm is a free brainstorming application for the iPad and the iPhone. The app allows you to record brainstorming sessions using a combination of free hand drawings and sticky notes. You can share and collaborate with other users of iBrainstorm. Sharing notes and drawings between users in a local setting is a simple matter of "flicking" an item to another user.
Applications for Education
iBrainstorm could be a great application for schools that are using iPads in a 1:1 setting. The option to combine free hand drawings and sticky notes makes iBrainstorm flexible enough to suit learning and creation styles of most students.