I found this proggy a few months ago and now find it comes in very handy so I thought maybe some of you will find this as useful as I do.
Its a program called MapZone and its got a plethora of options which would probably take you years get to know and use them all. I've got it installed in my PS plugins folder (sorry but I don't know if it works with PSP) although I think it can be run as a standalone program.
Updates, tutorials and so on can be found here:
http://www.mapzoneeditor.com/