That is the trick- creating a menu which loads first - from which you can then select an.iso you want to boot.
If you find an easy way of doing that - please let me know.
They sent me something they created for their own in house use - it is a bit industrial looking. Based on Grub , as it uses menu.lst to select from. I assume it saves them lugging mutiple dvd/usb's around. In any case, I can't get it work - except by booting it from the HD.
If you find another way that doesn't involve getting another dvd drive
- I would pleased to hear it.