I don't know you, but I've been happy with the Kinesis Contoured keyboard. I'm comfortable making this recommendation based on the fact that we're both on Hacker News (and therefore probably have some other things in common). If I knew your HN voting history I might be able to do a better job.
Taking advantage of social ties and external sources of information is definitely something that automated recommenders should be able to do. Few of them actually do it, however. As I mentioned elsewhere in this thread, recommendation algorithms just aren't very good. Once they get good (and fast), all sorts of external information will instantly become useful. Recommenders will be able to find significant correlations between the browser you're using and your preference.
I've looked at the Kinesis quite a lot, but have never been able to use one, so the cost held me back. One thing I like about it over other keyboards (Microsoft Natural, for instance) is that it doesn't maintain the leftward 'sweep' of the keys. The MS Natural is perfect for the right hand: fingers 'sweep' up and down along the axis of the wrist/elbow. But the left hand, while pointing the wrist in the right direction, forces a finger sweep that's now nearly perpendicular to the wrist. It's mindboggling.
So two things hold me back: I've grown to love 'short travel' keys: if activation was at 1mm I'd be ecstatic.
In reality, I'll probably order it here shortly: I need something that's more comfortable. Getting the foot pedal as well (for shift) is probably the best combination.
Do you use a foot pedal? If so: single or triple? From years of bad habits, I pretty much only use left shift and ctl (even going so far as to use my ring finger for QAZ): I think moving that motion to my feet would be a pretty good change.
Apart from eagerly awaiting your reply, I have to say: I don't see how our voting history would have much to do with our preferred keyboard layout.
Disclaimer: This is going to sound like a sales pitch, but I don't have any affiliation with Kinesis.
I'm only 25, but I've dealt with tendinitis in both wrists since I was 18 (me and computers have a love/hate going on.) The only real downside to the Contour keyboard is the cost. Effin' $300? Are you kidding me? On the flip side, they're so good that I actually own 2 (1 for home, 1 for work). They're amazingly comfortable, and have become the only keyboard that I can use for more than 20 minutes. I have a single footswitch at work, and a triple at home. Honestly, I wish the triple at home was just a single, as I only use one switch on it. That switch is the shift key, and saves my hands lots of "acrobatics" and time, especially when coding (special characters). A hardward Dvorak mode is just icing on the cake.
On the flip side, for a $300 keyboard, their support department sucks. One of the keyboards was exhibiting some really funky behavior out of the box, and they made me pay return shipping on the faulty keyboard. Obnoxious given that you assume a premium product like that would just work, and if not then they don't stick you with the bill. That just sounds like sloppy management, but the product is excellent.
Pair it up with a Kensington Expert Mouse (actually a trackball) and I can work away for hours on end with far less of the pain and fatigue I used to deal with.
If not, since you take the arms of your office chairs, I'm going to hazard a guess that you have wider shoulders than most keyboards are designed for. If that's the case, you might wish your Contour had either a bigger split or an adjustable split. I would be more interested in getting a Contour if I could have a bigger gap between the left and right sides.
I think this is my underlying problem with keyboards. I have very wide shoulders. I"ve had the most luck with the microsoft natural, but I find myself wanting to increase the split angle all the time.
Also having an ergo keyboard with low soft keys like the Mac would be awesome.
Taking advantage of social ties and external sources of information is definitely something that automated recommenders should be able to do. Few of them actually do it, however. As I mentioned elsewhere in this thread, recommendation algorithms just aren't very good. Once they get good (and fast), all sorts of external information will instantly become useful. Recommenders will be able to find significant correlations between the browser you're using and your preference.