My MacBook Pro has increasingly been creaking under the load, especially when I use it for Demos using VMware. So I removed everything I could and installed a 128GB SSD drive.
This machine has gone from being slow and clunky to being the fastest Mac I have ever used.
It used to take over a minute for my demo VMware image to restore suspend, and many more minutes for things to stop whirring and become responsive. Now it takes 12 seconds and the Windows side is immediately responsive.