Keyboard options--what works for you?

Using a flat keyboard is starting to hurt my forearms. I do a lot of typing, and that amount will only increase.

I’m looking into getting an ergonomic keyboard of some sort, and I’m also considering trying out the DVORAK layout, but I’d like input.

Last night, I switched to an old split keyboard of my husband’s, and immediately the pain lessened. That keyboard’s keys are quite stiff, though, and I would like to replace it with something with softer/easier keys.

I’m willing to invest, and I’m willing to use something weird like this system from DataHand or this system from Safetype, but I’d rather get feedback first.

Do you use an ergonomic keyboard? Like it? Which one? Do you use QWERTY or DVORAK? Is DVORAK easy to pick up if you’re 35 years old and a little set in your ways?

Other keyboards:

http://www.kinesis-ergo.com/us_versions.htm

I started to get twinges in my wrists & hands, and have a family history of carpal tunnel - I simply switched to a Microsoft Natural keyboard, because I found a new one for a song on eBay, and it’s done fine for three years. It’s got a straight split down the middle of the keys, a fairly ordinary key action, and an extra lip at the front which, for me at least, works as intended as a rest for the heels of the hands.