Multiple users & T42: Boot from USB w/o internal HD pass

[textpxy]

What I want to do is this:

-- When travelling, I want to work from the internal hard disk.
-- From home, I want to let other people boot off of an external USB hard disk, but I don't want any of the files on the internal hard disk to be accessible so that nothing can be screwed up. (I don't care if they screw up the USB drive.)

My plan is to try setting a password on the internal hard disk (which the home users wouldn't know) and specifying USB boot first. I'm worried, though, that the BIOS won't allow the USB boot to happen without the hard disk password. I don't want to order the computer then find out it won't work...

Has anybody tried this before?

Thanks!!!!!!!!!!!!!!!!!

JL