As Macworld's resident input-device geek, I've had the pleasure of testing many mice and mouse alternatives over the years. Here are my favorite current devices for moving a cursor around a screen (which means the iPhone's touchscreen interface doesn't count). They show just how far input devices have come since that first electronic rodent.
Logitech MX/VX mice
When it comes to traditional mice, Logitech is currently the top dog. The company's higher-end mice have long had great ergonomics, lots of customizable buttons, and excellent tracking, but it was the introduction of the MicroGear Precision Scroll Wheel in 2006 that pushed the company's mice to the next level. Made of metal instead of plastic, this weighted scroll wheel can spin freely; a gentle flick of your finger speeds you through page after page of onscreen real estate, stopping instantly with a touch when you find what you're looking for. (It can also function as a standard click-per-line scroll wheel.)
Selecting an input device ...
"This may not sound like much, but as I said back in 2006, in my countless hours of mousing about, this new scroll wheel has been the biggest mouse improvement since the scroll wheel itself--it even won an Eddy. To top it off, Logitech's Mac driver software, which has had a well-earned reputation for being glitchy, seems to finally be stable.
Check out our reviews of the MX Revolution, the VX Nano, and the MX 1100.
Kensington Expert Mouse
I'm a fan of well-designed trackballs; by using a large ball and smooth hardware, the best ones reduce repetitive fine-muscle movements and allow the ball's momentum to take you across the largest of screens with a single spin. And as far back as I can remember, the trackball standard has been set by Kensington. I purchased my first TurboMouse--the original two-button version--back in the early 1990s. I later upgraded to a four-button version, and then to the TurboMouse Pro, which added USB, a mouse-style scroll wheel, and six additional buttons." (Continued via PC World, Dan Frakes, MacWorld) [Ergonomics Resources]