Just because a setting is tucked away doesn't mean it can't make a big difference. Many Photoshop veterans, for instance, are discovering that cutting out Cache Levels and Image Previews can make the photo editing beast a bit more agile.
The tips and illustrations come from Make Photoshop Faster, one of those websites that seems to have grabbed a great URL early on. The steps are simple and involve turning things down or off in Photoshop, and if you like the pretty background of the page, you can download that, too. Those with very specific Photoshop needs might actually need some of the functionality of multiple Cache Levels and having Image Previews enabled, but most people can just cull a bit more speed from their exclusion. Thanks for the tip, Nathan!