We've already got Irreco for the tablets: http://www.internettablettalk.com/fo...ad.php?t=15919

All we need is a IR transceiver. (the referenced thread mentions some usb-based ones for $40 a piece)

I think that this could work quite easily.

Also, if you were interested in a more complicated hack, there's three different LEDs in the upper left corner on the N810 at least (I don't know about the N800). Unless you absolutely need Red, Green, AND Blue notification LEDs then you could replace one of them with an infared LED and replace the plastic "window" over the LEDs with some infared-transparent material I don't actually know anything about the feasibility of this as I have no idea how finely the LEDs can be controlled. (I believe they're accessible by DBUS commands)