5. PSP Analog JoystickIf you hate using the PSP's D-pad, then check out this nifty analog stick hack. Full instructions here.
This is a totally beautiful piece of art which works by utilizing a DIY mini usb type port to to the psp and a mini usb connector to an Analog Stick , this makes it detachable and adds scope to making different addons (steering wheel)[Source 1 - 2]
4. Nintendo Wii On the PSPA 16-year old modder managed to get his Nintendo Wii running on the PlayStation Portable, using Sony's LocationFree Player. Continue reading to watch a demo.
By patching through the PSP to LocationFree and by sticking what looks like a custom made Wii sensor above the console, the PSP can display the Wii's output using its WiFi to connect to the internet video stream, and a spare Wiimote to control the cursor[Source]
3. PSP Steering Wheel ModFinally, a more comfortable way to play your favorite racing games on the PSP. This modder wired a "PS2 steering wheel to the handheld's buttons and analog control" to make it all possible.
As the video after the break shows, the whole setup appears to work reasonably well -- or, at least as well as a full-size steering wheel hooked up to a PSP can be expected to work[Source]