Well you can boot from USB devices all already so just take the CD and copy it's contents to the drive and boot from it.
There wouldn't be any speed boost by going through an IDE channel because the thumbdrive itself is probably limited to either usb1 or usb2.
To do what you are saying you would need not just a cable but some hardware too because USB devices like thumbdrives need USB host's. That is why you can't connect your camera to your thumbdrives and transfer pictures. You need some host to interpret and pass along data.
I have never seen one like that. I'll keep my eye out though but I'll doubt one will turn up!