What you are seeing is what we call the "technicolor beachball" and it is frequently associated with hard drive issues.
First, you don't need any software beyond Mac OS (possible exception: DiskWarrior from Alsoft) to keep your system in good shape. But you do have to do a bit of maintenance from time to time.
Simply doing a "cold start-up" helps the computer because MacOS X does file checks at start-up.
Simply looking at the "xxxGB available" at the bottom of a Finder window MacOS X 10.6 and earlier) or doing a Get Info (⌘+i) on the HDD will tell you where you stand. A system drive should only be 50-60% full for best performance. Sata drives should have 15-20% free. Download free OmniDiskSweeper for Mac 1.8
to help you see what's on your drives.
Periodically, repairing permissions can help keep things running proberly. About Disk Utility's Repair Disk Permissions feature
There's more, but this is a good start.