Let me say joerg_rw and MohammadAG that we're all very glad to have you doing this work, it is really promising!
At the same time let me say in the most kind way: I am waiting impatiently like hell for OTG on the N900.
I hope some day it ends up in extras.

The N900 won't be able to power a 2.5" harddrive right? Has it been tested by someone here yet?
And USB gamepad of some sort would be interesting for some games and emulators.