I realize that some may find it odd that I wax rhapsodic about something as mundane as a computer keyboard, but those who've had the pleasure of using Apple's old Apple Extended Keyboard (code named the "Saratoga" for its battleship gray color and size) and have had to put up with lesser keyboards from Apple and others, will be thrilled to know that there's a modern, USB keyboard that's nearly as nice as the Apple input device of old.
That keyboard is Matias' $100 TactilePro. The folks at Matias use the same keyswitches found in the Apple Extended keyboard and it shows. The keyboard is a bit noisier than my old Saratogas (more clack) but it's just as springy and responsive. Like the older Apple keyboards (and unlike the current Apple offerings) the TactilePro includes a Power button for switching on and off compatible Macs (not all Mac models will respond to pressing this button). And like Apple's new keyboards, the TactilePro includes Volume Up, Volume Down, Mute, and Eject keys (F14 and F15 are used by Mac OS X to adjust screen brightness, though the keys aren't marked that way).
If you're in the market for a new keyboard I strongly suggest you check it out.