One of the regular complaints about the Sony PSP is its lack of dual analog sticks. Rather than berate Sony about it, however, one enterprising gamer over at AcidMods hacked together a workaround, connecting a DualShock 2 controller to his PSP.
Video demo after the cut
The DualShock hooks up to three new mini-USB ports placed on the back of the PSP, meaning that it's a non-permanent attachment. When you have a table or other surface to rest the PSP on, then you can use the external controller; if you're on the bus, however, you can continue to use the handheld's own buttons.
There's no tutorial at present, but the gang at AcidMods are trying to persuade "flasheur", the modder, to put one together. More details of how the two parts go together in the video below.