Yay!
So, no thanks to Nvidia support, i was able to finally crack the problem i was having with getting my 9800GT card working under Jaunty Jackalope (9.10). The secret? Read the damn X.org wiki.
Well, sort of.
Turns out the problem i was having was being reported in the Xorg.0.log file as "Failed to initialize the NVIDIA graphics device PCI:2:0:0", which is about as helpful as the old Tandy error message of "What?"
Digging a bit deeper into the /var/log/messages file showed a bit more information about what was going on. Specifically, around the time that the driver was being loaded there were a few additional errors being reported, including one line: "vmap allocation failed: use vmalloc=<size> to increase size."
So, i'll admit that this is also a delightfully cryptic message. A bit of sleuthing turns out that the problem is with the kernel configuration, which means that you'll need to modify the grub configuration. (Or you can interrupt grub, and manually edit the "/boot/vmlinuz … " line to add "vmalloc=256MB") If you do modify the /boot/grub/menu.lst file, be sure to run grub-update to install it.
That was all i needed to do to get things running, and now i have half of a dual head system. (While the second monitor comes up, KDE doesn't yet recognize it, so i've got :0.1 with, well, nothing in it at all.)
So in the hopes that someone out there could also benefit from this, have at.
Hmm… didn't stop me.

this is why people will not be adopting linux in droves anytime soon.