I'm using ArcGIS 10 and running the analysis on shapefiles.
I tried importing the shapefiles to a geodatabase, but it actually took look longer for the analysis (I only tested on the Intersect), another thing that puzzled me.
An update on this: I was running the script from a created toolbox in ArcMap...I have since tried running the scripts from the command line on my computer, and they run much faster, possibly as much as 5 times faster.
Thanks!
Cody