As wearable computing is in its very early beginning you should make various experiments and share them with your peers. Doing this with an open and versatile OS such as Linux should give you a lot of fun ( after all, desktop computer is just a plain vanilla computer), because you play with both the OS and the hardware. If you are unsure of the technical decisions you are going to make, you can start with a proven design. On the net you can find the specifications of some wearable systems thus you will not have to reinvent the wheel and you will avoid some pitfalls. ( the designs are sorted by alphabetical order ).