Well, You could do what I did and get one of those PSP Sharge Sync Cables, which have bot a Mini USB as well as a PSP tip, and you can charge it over USB.
So you get the best of Both world, use you existing AC adaptor, while still be able to read when charging, when using the PSP tip.
I originally got the retractable
Logic3 Data And Charge Cable (PSP)
Its really handy, and I still use it for other stuff, though I passed on my PRS-500