What is the Backpack, you ask?
The Backpack will be an open hardware based addon similar in style to the sliders used on Compaq(HP) iPaqs. It will be self contained in that it will carry its own battery source for powering USB peripherals and also a few built in goodies such as a camera module, stereo speakers(possibly amplified), and possibly a GPS module.
This thread is to help others who may want to build a similar device and to accept input from the community on its design. PLEASE, refrain from any flame wars or other similar postings.
Feel free to post with suggestions, comments or even criticism(as long as it is constructive).