Nintendo DS: Great system. Decent graphics (7/10) and good sound (8/10). The system is good and I like the touch screen. The system has a chat system and a wireless (internet) connection, although you have no browser (but Opera is currently making a browser for the DS just like the PSP). More original games. The system was made more properly. It's made with the same material as bullet-proof glasses (meaning if you drop it, chances are it won't break, I dropped mine about 20 times and you can barely tell. The system works just as good. But if you drop it, re-calibrate the touch-screen).
Final Score: (8/10)
Playstation Portable: I hink this is a really great system. I love the games on it, especially GTA (Grand Theft Auto). The graphics are a lot better than the DS (9/10). The sound is a lot better too, can play louder. This has an internet browser (which you buy seperatly, however). This holds music files (mp3) and pics (Bitmap, PGN, etc.). You cannot chat with people, unlike the DS, though. Most games don't have Live play either like some DS games.
Final Score: (9/10)
I would rather get a PSP than my DS but, w/e, I'm cool with it. A PSP costs more money than a DS though. A DS is about 120 if you get the lite and about 200-250 for PSP.