itsgood... PSP = PlayStation Portable.
Personally, while I greatly dislike Apple right now, I do have to admit that I'd lean more to the iTouch. But, if you're thinking of playing any real games at all (why not, racing games, etc are a blast when you need to waste time), the PSP is definitely the way to go. I know you can download lots of games to the Touch, but there's really no comparison.
There's reasons to go for both, I guess it just comes down to personal preference... which feels better in your hand? And if you get a Touch, don't forget that you can't change the battery, so the extended warranty may come in useful.
As to waiting until September, if you don't need or really want it yet, go ahead and wait. If you think you'll use it plenty now, don't bother. 
Good luck Future_Chef!
