I swapped the power and back keys by swapping the two functions in all the files in /system/usr/keylayouts. The only caveat is that when the phone is locked, you need to use the real power key (not the slider) to unlock it. Otherwise I think it's much more usable when portrait browsing.

I also found so source code available from the android-x86 project to implement touch gestures for those functions in android 1.6 (I believe). I have no idea if it will work in 2.2, but if anyone wants to take a peak at the source in question it's here: http://git.android-x86.org/?p=platfo...d85b69fdb2133d

Javispedro: it also works with the .04 kernel for the most part. So you don't HAVE to use the new one if you don't want too. It's a good idea to use the latest though.