With this T-type breakout board from Cyntech, you can easily break out the GPIO pins of the Raspberry Pi on a breadboard to quickly start prototyping. The ribbon cable comes at the side of the breadboard so it won't be in the way while working on your project. This breakout also has the possibility to provide +5V and +3V3 to the powerrails on a breadboard.
This breakout board isn't soldered. Soldering takes about 10 minutes. 40-way cable included.