The default disk cleanup utility in windows that cleans the older system restore points is a drag. I am currently using tune up utilities 2009 just to clean up the old system restore points and then i run CCleaner to complete the clean up. You could certainly make it a lot easier for me if you included this feature. Leave it disabled by default so that only advanced users turn it on.
Moreover Vista doesn't allow you to control the space used by system restore. It defaults to 15% of the C drive. This usually takes up a minimum of 5GB in my case.