Last week a fault was found in Lumines that allows PSP owners to run whatever code they want. This exploit lead to a downgrader, allowing PSP owners to downgrade version 3.50 PSP's to version 1.50. PSP's at version 1.5 can run almost anything, including homebrew and pirate ISO's.
I am not interested in downgrading my PSP, I'm happy playing Killzone: Liberation and I'm happy paying $25 for the right to play it. But some people will do anything to run homebrew and/or pirated games.
I happen to have 2 copies of Lumines, yeah 2. That's because I used to play against my girlfriend. I saw that Lumines sales had gone up 5000% in America and checked eBay to see if the same thing was happening here. It is! and lumines (previously selling for less than $20) is now selling for $50 plus. I listed both my copies in 3 day auctions and I am set to make $50 each of these games, and they only cost me $25 to begin with. Pretty sweet hey?