I'm laughing right now, even though I'm feeling a bit foolish. I got it all mixed up, and getting the keyboard to work was so easy, lol.

Short explaination: You did it, man! All I had to do to set the layout to abnt2 (the layout most keyboards come with in brazil) was choose Brazil as language, rather than look for an abnt2 option in the Layout dialogue. Extkbd IS abnt2-compatible, making the package fully able to localise external keyboard input to the N900. Lot's of kudos due here!

Long explanation: I always assumed the Language dialogue in extkbdd referred to the keyboard map one wanted to load, while it seems Language is responsible for the keyboard's geometry/layout. This would explain why at first, while using a SU-8W, I tried loading Brazil/Portuguese in Language and got weird results.

I'm now using the SU-8W with Language set to USA and Variant set to intl; this gets all the weird symbols, the diacritics, to work. And in order to set up the old Compaq keyboard I dug from the basement, an abnt2 layout keyboard, setting Language set to Brazil, no variants, loads the correct map, and it works like a charm.

I guess the Language descripton in that dialogue might be a bit confusing.

My issues are over, keyboard and mice are working great. I should add that I'm using that firefox mouse fix you shared, way ago in azerty1's thread, to get a mouse working in Firefox. It has since become my main browser; this is being typed in FF4 RC1, btw.

Keep up the good work, man.