What all can a 3DS do?

Answer 1

Some of the highlighted features of the Nintendo 3DS are as follows:

3D Top Screen: The top screen is capable of displaying autostereoscopic 3D using a parallax barrier. This allows your eyes to perceive 3D depth without the need for glasses.

StreetPass: The 3DS can exchange data, such as Miis, with other 3DSes that it comes across while in Sleep Mode.

Simplified Friend Codes: The 3DS features a friends list universal to your system and the games you played on it. Friend Codes are now assigned per-system instead of per-game.

New Controls: The 3DS's Circle Pad allows for 360-degree analog controls. The system also has a built-in gyroscope and accelerometer to allow for motion and tilt controls.

HOME Menu: Improving on the DSi's menu, the 3DS allows you to suspend a game in progress by pressing the HOME button. From here you can launch into another application or utilize the game memo or browser, then return to the game in progress.

Mii Maker: The Mii Maker has the ability to create a Mii with your facial features by taking a picture of your face. You can also export your Miis as QR codes to share with other 3DS users and import a Mii from the Wii's Mii Channel.

If you want to see more of what the 3DS can do, click the link below.

Answer 2

It has one camera in the front (facing you) and TWO facing the outside. It also will play regular DS games and its own 3DS games that will make the game 3D. The pictures you take and Netflix videos will also be in 3D. The cool thing is that you don't need any 3D what so ever. (unless you have bad vision like me)

Answer 3

The 3DS memory card is for downloaded games and their save game data. It contains your streetpass data, and you can add music to it too. Photographs and videos you take using the 3DS can be copied to the SD card also.