I can has some. 
I've been obsessing about this for a while now. Today I finally received my Seagate 7200.3 320GB 7200 RPM 2.5" SATA drive (ST9320421AS) for my MacBook, as well as a macally FireWire (PHRS250CC) case to house my old 80GB drive. It's liberating to have more than 2GB of disk space free. I'm expecting slightly worse battery performance due to the faster drive speed, with the potential for some speed improvements for the same reason.
The install went off without a hitch. I booted from the Mac OS X 10.5 install disc and cloned the internal drive to the new drive (temporarily in the macally case) using Disk Utility. After maybe 90 minutes the process finished and I booted from FireWire to make sure everything was kosher. One quick drive swap between the macally and the MacBook and I'm in business.
Now to see how many weeks go by before another drive is filled.
(As a side note, Mac OS X decided the existing Spotlight index was bunk, and my fans have been spinning like mad while it's rebuilt. I wish it wouldn't do that on battery power.)