>> But wasn't the conclusion of this discussion that you can just buy >> one, connect it to computer only for booting, and then disconnect >> it and use on another one? > >He needs to be able to enter the encryption key at boot time. >Opening up the case and temporarily installing the motherboard >serial cable doesn't seem like a good solution.
This may or may not sound stupid, but wouldn't an USB security key perhaps work for this use case? No keyboard or serial port needed.