Yes, I tried the driver you sent, but unfortunately that driver was for the CompactFlash USB reader, not the SmartMedia USB reader. I was meaning to write you with an update and thanks for the effort, but as it turns out, you caught me on here too! :-)
Anyway, good news! I found a way to get it working. Turns out I owe thanks to a writer on an unrelated comment on microsoft.public.win2000.hardware who was mentioning that their Delkin Devices eFilm reader was working great for them under Win2000. Desperate to try anything, I decided to give those drivers a whack.
Guess what? It works! You do have to do a bit of tweaking. Namely, take the Win2000 beta driver from: http://www.delkin.com/dd_support/download/Reader-4_Win2000.EXE
Copy the contents into a working directory. Then, assuming your Imagemate Smartmedia is detected as a vendor 781/prodid 0200 like mine (look around in the registry [carefully!] for the entry under ControlSets to find the detected pair), edit the .inf file to add your reader.
You have to make 2 edits, namely one near the top, and one near the bottom. Copy the existing line for the eFilm USB reader, then modify the ven# and prod# to match what you have, save it, then go through a windows hardware detect and point Win2000 to that directory.
Worked great for me, at least until Sandisk comes out with their official drivers. Thanks for all the help folks!
Jay