Inspired by a product called ScanCard (which is a special binder with pockets for capturing information on 3-inch sqaure index cards), Tammy Cravit has created similar implementation called Post-It Portable Workspace:
The basic idea of the PPW is simple: I took a series of plastic sheet protectors, which provide a nice surface for Post-it notes to adhere to. Inside them, I placed sheets of card stock (file folders, cut down to 8-1/2 x 11) for rigidity, and I put the whole mess in a 3-ring binder.
Then Tammy creates different contexts on different sheet protectors. Pretty cool idea, I like it a lot.
Introducing the Post-It Portable Workspace – [The Wanderings of a Wanton Wordsmith]