Should I get the PSP?

[Badonkadonkhr]

I want to get a portable game system. I don't know if I should get the PSP or not? Is it worth it? Will there be another one in a couple of years? I have a $290 credit at gamestop and have bought everything for the ps3 that I want. I could buy another controller and more games when they come out or I could get the ps3 daxter pack snd maybe one more game. Can you actually play psone games on it? I need help.  Also , I don't want a ds , I sold t to gamestop. Thats why my credit is so high.