Basics
As of March 2010, the Nintendo DS costs around $130, while the PSP 3000 goes for about $170. As far as graphics go, the DS is capable of graphics similar to those on the Nintendo 64, while the PSP has the slight graphical edge with graphics similar to the Playstation 2. The DS offers more protection, as you can close it and protect both screens, while the PSP screen is always exposed. Both are high-resolution LCD displays; the PSP has a 480 x 272 pixel screen and the DS has 256 x 192 pixels per screen.
Innovations
While the PSP has the best graphics of any hand-held system to date, Nintendo rarely shoots for sheer graphics ability when releasing a new system, focusing instead on innovation. For example, one of the DS Lite screens is a touch screen. This leads to new and inventive ways to play games through touch-based controls. The PSP doesn't really offer any innovative features new to the video-game scene.
Features
The DS is a very good gaming device, but it doesn't offer much else in the way of additional features. There is Pictochat, which allows up to 16 people to chat and draw pictures over a network, but the feature is rarely used and gets old fast. The PSP, on the other hand, is a full-on multimedia device capable of playing music and movies, with other features such as Internet radio, Skype and streaming TV. The battery only lasts five to nine hours, however, which is less than you'd expect for a multimedia device.
Game Library
While the PSP has great games like God of War, Tekken and the stellar Final Fantasy titles, it can't compete with the DS in this category. Nintendo is famous for releasing excellent first-party games for their systems, and the DS is no different. The DS's first-party library consists of multiple Mario, Zelda, Pokemon and Metroid games, and they all have garnered good reviews for the most part. You can also play Game Boy Advance games on the Nintendo DS through the second cartridge slot.
Controls
The Sony PSP control scheme is reminiscent of a Playstation 2 controller (complete with an analog stick), which comes in handy for moving around in 3D games. It also features the standard D-Pad. The PSP has the standard two shoulder buttons, four face buttons--X,O, square and triangle--a start button and select button. The DS has only a D-Pad, two shoulder buttons and the A, X, B and Y buttons. Though the DS is missing an analog stick, it makes up for it with the touch screen.