NERD ALERT!
I'm a big fan of mechanical keyboards, myself. They won't help much if your typos are mostly missed keys (like mine), but if you ever just miss a character because the key didn't depress quite enough, the mechanical switches can make a big difference. Mostly, I just like the tactile feel and clicky sound. I type about 20 wpm faster on mechanical switches.
Prices vary quite dramatically, but as they've become more popular among gamers, there are some competitive prices out there. I just picked up and have been happy with the
Azio Backlit keyboard. It uses Kaihl switches, which aren't quite as nice as Cherry, but they still feel much better to me than any membrane switches. ETA: The white backlighting can get CRAZY bright.
If you are looking for a quiet typing experience, something with Cherry Red or Brown aren't "clicky" and require the least actuation force of the major switches. If you've used membrane keyboards for a long time and have never thought that they felt too "squishy" or imprecise, then you can probably safely disregard all of this.
END OF NERD ALERT