Operation Ubuntu: success.
Title speaks for itself. Finally booted it natively and from the hard drive, despite my machine's dislike of anything other than XP. Worked the kernel parameters in GRUB a bit, and it booted quietly and perfectly. Concerned about a few lag issues, but that should be worked out quite soon.
(Edit: Ubuntu showed me an ATI driver that I hadn't installed. I'm now running smoother than a well-done analogy.)
(Edit II: I opened up a terminal window and installed XGL, so transparency, shadows, and a lot of other cool effects are supported. Like paper-flipping window drags.)