I've heard of the Dvorak keyboard layout years ago, but it wasn't until recently that I became curious and discovered the whole point behind it and what it really is. At the same time, I found out that there have been several layouts designed to improve upon either QWERTY or Dvorak, most notably (to me) the various Capewell layouts (C-QWERTY, C-QWERF, C-Dvorak, Capewell Layout 0.9.3), the Asset layout, the CarpalX layouts (especially the "fully optimized" and "partially optimized" layouts) Colemak, and the Workman layout. Lots of interesting info at each of those projects' web sites. I honestly never had a clue that so much work has been put into QWERTY alternatives. Hell, for that matter, I've never even seen a non-QWERTY keyboard!
Anyway, I plan on giving several of them a try at some point, but I had to start somewhere. I decided to start by learning the "original" alternative, Dvorak, partially because it is available everywhere (Microsoft has even included it with their operating system since Windows 95, apparently). Although I later found that Colemak is not only available in my current OS (openSUSE) but it has been in many Linux distributions for years. Ah well... too late. It'll most likely be the next one I try; it's really piqued my interest. It's still not everywhere though; I noticed that it is not available in Finnix, although a small handfull of localizations of the QWERTY layout, as well as Dvorak, are available.
I honestly don't care too much about the Ctrl+Z/X/C/V shortcuts, and rarely miss them, but I have noticed some of the other Dvorak problems I've read people complain about--especially the heavy use of the pinky and the bizarre location of the "L" key ('ls -l' really is a bitch to type). Meanwhile, I find that I need the "W" and "V" relatively frequently, but those keys are in incredibly difficult-to-reach locations. So far I've typed this entire post up in Dvorak, and in my time with it so far my right arm/wrist hasn't been feeling quite as weird like it has previously. It's too early to say whether Dvorak is in fact helping, or if it's simply an effect of me typing so damn slow all of a sudden (I used to type QWERTY at 50-70WPM, occasionally 80WPM if I really focused and didn't screw up).
I'm actually surprised I'm starting off as well as I am in terms of key location and accuracy considering the extreme differences between the two layouts. I expected far worse from what I read. I am using temporary "training stickers" on my keyboard for quick reference until I learn, or simply an image on the screen occasionally (on-screen image is the way I started). I have been tempted a few times since beginning to learn Dvorak to temporarily switch to QWERTY since I am so far not very productive at Dvorak, so I didn't exactly quit cold-turkey. The JavaScript tutorial over at http://learn.dvorak.nl/ has been an amazing help... through the Colemak page I found out about KTouch, which I'll probably start Colemak with. But are there any other good ones for Colemak?
By the way... I was once against removing the Caps Lock key, and I am still against doing away with it completely. However, I was convinced to give it a try, partially because KDE allows allows Caps Lock to be mapped as pressing both shift keys (which is how I set my system up). And you know what? I'll be damned, that extra Backspace really does help when learning a new layout! I remember back when I first learned QWERTY, one mistake requiring a round trip to Backspace and back to home row would misalign the right hand triggering a half-dozen more errors in rapid-fire succession before the problem was corrected. By comparison, caps-lock-as-backspace combined with Dvorak's heavy use of the home row) really simplifies things.
I'm anxious to give Colemak a try, but I'm not sure when I will yet; I have a feeling it's not a good idea to screw around with a third layout while still trying to learn the second.