Running Ubuntu from a USB Flash Drive

Okay, so I have now wasted many hours going through forums and forums of information, tips, "THIS WON'T WORK"'s and "maybe if you try this"'s, and now I feel I'm very, very close to having Ubuntu working on my USB Flash drive, but I've hit a wall, and I'm not sure what I can do to get past this point... So here's what I've done so far -

1) Downloaded Ubuntu 11.04 and rEFIt

2) Burn Ubuntu to a CD

3) Launch Ubuntu on the CD, install on the USB Flash drive, leaving a partition for rEFIt, another for Linux Swap

4) Boot into OS X, launch Disk Utility, mount rEFIt

5) Erase empty (not Swap) partition

6) Restore the now empty partition with the rEFIt mounted drive

7) Restart the computer, holding down ALT

8) There are two options, Macintosh HD (or something similar) and rEFIt - clicked rEFIt

9) rEFIt recognizes there is Ubuntu on a flash drive, try to run it

10) End up with a black screen saying "No bootable drive, please insert a bootable drive and press any key"

Aside from not being able to find the "any" key (yes, I know, lame joke, but if I don't laugh I'll cry), what can I do to make the computer recognize my flash drive as a bootable drive? On the rEFIt support page they say to put the "elilo" and "vmlinuz" files into a new folder in the "efi" folder, but I can't find the elilo (or it's variations). Any tips? Work arounds? Has anyone actually got a USB Flash drive to run Ubuntu on their Mac (despite the many, many, many times I've been told it can't be done)?

Thanks for any suggestions