Cool, I've never seen that before. It looks like uses a USB drive and has a GUI built with gtkdialog (which maybe I should check into.) My script uses CDs or DVDs, mainly because I have a bunch of those but only one spare USB drive (and it's just 1GB).
Other things that share a similar idea are UNetbootin and ULTILEX.
In other news, v5.8 out:
#v5.8 - Added Windows 7 recovery disc plugin. Incorporated fixes for Arch Linux plugins. Various bugfixes. Step 1 now run as root again (there were file permission issues) but still checks md5sums first. (September 17, 2010)