Here's my shot at PSP text input: Fast Analog Circular Text ;)
You select a pair of characters by pointing the joystick in its general direction, then write the left char with cross and the one on the right with circle. Square = backspace and triangle ends input. L and R switch left or right to another circle (repeating).
So, at most you'll need 2 keypresses, but in the usual case (lower case letters) you'll need only one. I plan to have a moveable caret soon. (left/right = 1 char left/right, up/down = beginning/end)
At first I wanted to do it like that (1 char per direction, not 2 grouped) but when testing I realized that with the limited precision of the PSP's analog stick having only half as many significant directions is preferable. I then wanted to make 6 circles instead of 3, but luckily I had the idea of this grouping instead.
As I said, it will be used in my game. I wanted to release that today, but now my friends drag me off to play billiard or somesuch strange RL activity, so it may not work out.