See our full review here. Here is a short commercial video from the manufacturer.
Evoluent Vertical Mouse 4 Right Hand – USB
Despite the fact that I don't currently use it myself, the Evoluent vertical mouse is the #1 ergonomic mouse I would recommend to most people. While it may not offer all the benefits of more advanced ergonomic systems, it also doesn't scare users away with a weird appearance or force them to take special training. Anybody who has ever used an ordinary mouse should have no trouble adjusting to an Evoluent vertical mouse.