This may be old news for most of you, but it's new to me. I was watching The Screen Savers and they were talking about AnalogX
http://www.analogx.com/contents/news.htm and their utilities. I downloaded cache booster (Boost your systems performance by tweaking your harddisk cache...) and maxmem (Ensure you have all the memory you need for your programs to execute quickly with AnalogX MaxMem...) they both work great. Here is the download index.
http://www.analogx.com/contents/download/system.htm