Drat, sorry. I thought I was on to something there...

Yikes! Sorry about that. Yeah, the biggest problem with remote controls these days is that many manufacturers are too lazy to set up their protocols properly; most protocols have a "device code" of some sort to uniquely identify a model of device (even the ancient NEC protocol allows you to choose 65536 different device codes), but manufacturers end up using the same device code for different models, allowing for cross-talk between different remotes. So there will probably never be a "clean" way to scan for any given key. Please be careful when using this!

Ah, unfortunately, there's no good way for the N900 to actually know when an IR command has actually triggered some external device. I'm really relying on the user to hit the pause button when something happens here.

Actually, you don't have to use the automated scan at all; the first row of four buttons lets you do a "manual" search -- you can step one at a time through the list with the "next" and "prev" buttons, and move quickly through the list with the "fast forward" and "reverse" buttons. They generate "Power" commands in exactly the same way as the automated search does, but only run for as long as you hold down the button. (And, in fact, you can pause an automated search in the middle and switch to the manual buttons to find a particular keyset with precision...)