Nice. I've used larger versions of that design. They work, but not terribly well. :-)
I have some contributions for this topic...
The Spyderco Introvert is a folder with a finger hole that also acts as a flipper. I love finger hole knives. Despite the odd design, this one works quite well.
The Spyderco Pochi works well as a small folder, but it also look like an adorable little dog.
The Ian Sinclair CardSharp 2 is a blade that folds down to the size of a credit card. It isn't a great knife, but it works as an emergency backup. I do wish it were available with a better steel.