Second vote for Colemak here! I spent the first two of my high school years in Japan essentially being homeschooled. I had developed shoulder pain and a ganglion cyst in my wrist due to lots of typing and playing tennis, so I took the opportunity to try both Dvorak and Colemak.

I used to average 110 wpm on Qwerty. I started at 30 wpm Colemak and reached 80 in three months. After fourish years, I'm back at 110 wpm, with no more cyst or shoulder pain.

I tried Dvorak for a week but disliked that 1) it emphasizes hand alternation (as opposed to Colemak's emphasis on finger mashes) and 2) it was so difficult to type "ls -l".

I haven't actually tried an alternate keyboard layout yet so I can't vouch for it, but Colemak seems to have the edge on Dvorak.

I also do the ls -l thing all the time and finally succumbed to just uncommenting the relevant alias in my .bash_rc. 'll' just makes it easier; I don't know why I resisted enabling the alias...

thanks for the link vacri!