Hardhat has just released his new Homebrew, PSPFlash-Cards v0.1 2006-04-30. -- first release
Toss the psp folder from this zip into the root of your memory stick. It'll work with the Grand Theft Auto: Liberty City Stories exploit, could be KxPloited if desired. The directions are on screen.
To customize the lessons, just edit the flashcard.txt file in the psp/game/pspflashcard folder and provide your own questions and answers.
No word wrapping for long lines, but it could be added upon request.