wurst wrote:
...
Which reminds me: as far as Linux is concerned there isn't much of a difference between USB Flash drive, USB HDD or internal HDD.
The only problem with USB drives and different computers is that different computers can make the same USB drive /dev/sdb, /dev/sdc, /dev/sdd, etc.; and GRUB doesn't like that. That's why you'll maybe need another boot loader. Look here for a hint or two
http://en.wikipedia.org/wiki/Comparison_of_boot_loaders .
P.S.: Something from the SYSLINUX collection is what you probably want.