Judging by other products, I'd say that handheld trackballs seem to be all the rage. This diminutive finger trackball takes portability one step further, requiring only your thumb and forefinger to use it.
The finger trackball looks like a device for travel use more than anything else, given it's one inch by one inch. And, likely due to its small size, it's still tied to your computer via retractable USB cord. The trackball is even LED backlit, so that it glows red while in use.
I'm not sure how much more efficient this will make you, but at least you can wow fellow tech lovers with your sideshow gadgetry. If you live in Japan, you can get one from Sanwa for roughly $US28. [Sanwa via CrunchGear via Dvice]