Now looking for PSP games

I started an earlier thread back when the Nintendo DS was the latest hot thing. Specifically I was looking for good games for the youngins. Now that we have the PSP, I am on the prowl again.

I just picked up Mercury for the PSP two days ago and am pleased to report that this is a GREAT game for kids and adults. Its a blob of mercury navigating through a maze wrapped in a puzzle wrapped in enigma... But seriously, seven-year-old took to it immediately and loves it.

Anyone else got some good PSP recommendations?