Yea, the PSP is more expensive by about 40+ dollars and it does have internet functions. I don't think it has WiFi, but it might. The DS has a touchscreen and uses game cards and catridge save while the PSP uses game discs and a memory stick.
ill name wats btr: PSP= Games, Graphics, ability to hold music, can play movies, easier controls, controls cant get lost. ONLINE PLAY DS= Touch Screen. Diliss thingy can get lost easily if not careful. Can have voice activated games. And wi-fi
And the DS Lite has INTERNET, YEAH!!! And you can buy an iPod to play music for your DS and it will still be cheaper YEAH!!
I bought my brand new one for 150$ there not that far off in price, so DS+worthwile iPod= more expensive. You can't surf the net watch movies listen to music on a DS, so PSP is better. plus better games, better graphics, and sony kicks ass.