The OCZ Mini-Kart redefines the meaning of thumb drive. While regular USB sticks are your full thumb's length, if not more, the Mini Kart goes merely to your thumb's first segment. With a height of only 2.8mm it is ideal to go into your wallet. This makes it possible to carry up to 2GB of storage around without having to track another thing in your pockets.
Compared to the high-performance USB drives you will definitely see reduced performance, but ultra-portability has its drawbacks. If you really think you can't wait an extra 30 seconds and you know that you will have a ton of tiny files, you may be better off considering the OCZ Rally which offers the highest USB stick performance on the market. For most other users the Mini-Kart seems to be a viable choice, also considering the competitive price of $65 for 2GB.