2 3D screens. 1 is touch. It's harly larger than the PSP, but has same amount of buttons, along with an addon mic. They both have 802.11b networking/gaming. And their graphics are very very similar. the PSP uses disks, the DS gets' hours longer battery. The PSP's screen is slightly larger, the DS's screens can be combined into one for a large screen, or can do two complete seperate things. Do some research before you come here saying it's ugly. It's not thicker, and hardly bigger in other ways, to the PSP. You'd know that if you actually researched it.
They are both great systems, and I will probably end up with both.