Now that you've finally got your hands on a Raspberry Pi® , you're probably itching to make some fun embedded computer projects with it. What you need is an add on prototyping Pi Cobbler from Adafruit, which can break out all those tasty power, GPIO, I2C and SPI pins from the 26 pin header onto a solderless breadboard. This set will make "cobbling together" prototypes with the Pi super easy. Designed for use with Raspberry Pi Model B AND Model A, both revisions.
The Adafruit Pi Cobbler is compatible with both versions 1 and 2 of the Raspberry Pi Computer - for version 2 computers, note that the GPIO #21 has been replaced with GPIO #27 and that the I2C pins are now I2C port #1 instead of #0. All other pins are the same.