RestoreIt! 3 is a data recovery tool that allows you to create multiple restore points. If your hard disk fails to boot, becomes infected with a virus, or even if you just accidently delete a file, you can restore the drive to a previous restore point. The restore points reside in their own hidden partition, and should be less vulnerable to corruption then alternate methods of safeguarding your hard disk's contents.
Unlike Roxio's GoBack 3 Deluxe, though, RestoreIt! has a limited usefulness. Basically, it can create what FarStone refers to as a Static Restore Point, which is a complete and permanent backup of at least your boot disk. It can then create Incremental Restore Points, which contain the differences between the Static or last Incremental Restore Point and the current Incremental Restore Point. It does not afford any more granularity than this, though, so you cannot restore just a single file. You have to restore the entire restore point.
GoBack, on the other hand, can show you a chronological log of all hard disk activity, and allows you to recover a single file if you wish. Although RestoreIt! provides good protection, it is a brute force method of data recovery. Even the System Restore feature in Windows XP provides more detail concerning a given restore point.
Overall RestoreIt! 3 is a good solid solution, but given the mature state of other solutions, such as GoBack!, I would not recommend it.
