You could also use the
Rhodium Keyboard Controller over at xda. This is a remapping tool that will allow you to map
any hardware key you like. It has a specific action called "Screen rotation" that you could map to ANY key, and either choose a key to do this either when you just press it, press it twice quickly, long-press it, or even when you press it in conjunction with the Fn key...your choice. However, if all you want to do is screen rotation it's going to be overkill.
On the other hand if you also want to
get the old "CTL+C/CTL+X/CTL+V" functions back if you're missing that ol' CTL key, or
map up/down functions to the volume up/down keys in every app but the phone app, and so on...then this is your app
