If you have not used the software before, it was originally released by R-Comp for the their 4te Pi machines. PiTools is the generic version which can run on any Pi machine (it would be nice if R-Comp fixed the title).
PiTools brings together a whole selection of really useful features to control your Pi, including a VNCserver, a screen lock, and a huge range of configurations to tweak your Pi and make it work better for legacy games and functions. I always have it installed on my machines.
One word of caution is to be careful with the Open Firmware. If you upgrade your machine and it is not a standard setup you can stop it booting. Just be careful and if you don't know what it does, you don't need it.
For me the most exciting feature of the 1.20 release is the inclusion of the DeleGate software which adds a recycle bin and protection for not accidentally deleting your !Boot folder. It deserves a separate review....
