Update on this one, guys...
If you just want the new theme, here's how I did it, without adding things to Synaptic.
Open your browser of choice and go to
http://hpmini.archive.canonical.com/.../hardy-hpmini/
This should give you links to click on; click on Universe and then Binary-lpia. In here, save the glassy-bleu-browser-skin_0.5_all.deb , glassy-bleu-theme_21_all.deb , and gnome-backgrounds-hp_0.4_all.deb files. Just save these to your Desktop. As these are compiled with "all" rather than "lpia", these should be global files that will work for 386 or 64-bit distros. Click on the files on your desktop and Package Installer should handle the rest.*
Presumably, you could go into the main, restricted, or multiverse folders and do the same thing for any .deb files that do not have lpia in their name and have them work on your distro.*
*standard disclaimer of me not being responsible for you hosing your system while trying to follow these instructions does apply here; they worked for me, though.