I don't understand the obsession with bluetooth (;

I have a [very generic] "Vuescape 2.4GHz wireless keyboard". I fished it out of the bargain bin at MicroCenter for $13
It's RF and comes with a small usb dongle.

I think I made out like a bandit. The last WIRED keyboard I bought was $30 (granted I specifically was looking for volume knob). I couldn't find any RF keyboards for less than $30 online either.

Anyway, with usb host cable and N810, it's just plug and play

Too bad there is no tv-out for N810 or I'd be set (also unfortunate that a mouse doesn't work reliably with it)