People with repetitive stress disorders, also known as wimps, might like the Wow Pen Eco. Its name is a bit of a misnomer, since it has very little to do with a pen (well, it does offer hand recognition with the right software) and doesn't really echo or anything. That said, its design is such that it's supposed to help people with things like carpal tunnel syndrome by easing pain. The vertical orientation of the mouse may look odd, but it functions just the same as your trusty two button mouse, complete with scroll wheel on the side.
By aligning the buttons vertically, the company argues, "you don't feel almost any pains and fatigue over the regular mouse." That's the kind of language you can trust. The spacing of the buttons was also taken into account, and are supposedly located at just the right spot so that you "never feel any inconvenience" during use. Just combine this with other ergonomic nonsense and you're well on your way to believing you're more comfortable than you really are.