PSPet has released a rather cool InfraRed Remote Control app for the PSP, heres what it says on his site:
Install the proper version on your Homebrew compatible PSP
Run the program on the PSP
At the start page, select the device you want to control (RoboSapien, ICybie, Media Center)
Use the PSP as an IR remote control for that device.
The buttons are labelled on the screen with the commands.
Certain buttons (like LTrigger and RTrigger) can act as shift buttons. Hold those buttons and new options will show up. Keep holding the shift button and press the regular button.
When pressing a command button, aim the top of the PSP towards the device's IR receiver
Press HOME to go back to the main screen to change devices
Press HOME again to exit the app