what about using the spare drive for temp and paging files, if you want to get more creative you can move the my documents folder off the c drive as well in a couple of clicks, open start menu, right click and properties on my docs and hit move.
i have windows on my 150gb raptor, my docs, downloads and stuff on the 1tb samsung along with the temp files & my paging file on a 80gb partition on a 250gb maxtor i didnt know what to do with.
you can move temp files from enviroment variables in system properties > advanced.
im considering moving temp files into the paging files partition to take the load off as the paging file doesnt do much unless an app's loading (its fixed)