Remember the GripShift exploit I posted about a while ago. Well, here is the SDK that allows you to create homebrew for it. The first game, a Pong game, has already been created for it.You are going to need the GripShift exploit to do this and also the SDK. Make sure you read the readme of both of these. You can run the exploit from any firmware from 1.52 to 5.02 on the PSP 3000.
To download the SDK: CLICK ME