Apple Teaches an Old Mouse New Tricks (or a New Mouse Old Tricks)
For starters, the Mighty Mouse is Apple's first two-button mouse. The "buttons," though, are squeeze buttons. A top button uses a touch sensor, like the touchpad on a laptop; in addition to the up-down motion of a scroll wheel, the Mighty Mouse's top button provides a complete range of movement. The mouse retails for $49, and is compatible with PCs as well as Macs.
Russell Beattie put the Mighty Mouse thorough its paces and waxes enthusiastic on it, as have others who have tried it. Critics, however, have expressed surprise and disappointment that it is not wireless, and feel that the design is unintuitive.