I've used Screen Captor, from Donation Coder, but you have to register, and I didn't find it to be all that great. It is free though, and can run from a usb drive. It might suit your needs.

I found this, but haven't had a chance to test it for you. http://www.nbxsoft.com/screen-recorder.php
If you want to read about, and compare the two you can access both websites here:
http://100-downloads.com/search.php?q=screen

thanks guys, i'll have a look at them