Links
Here's a compilation of helpful websites around the web. (Do not underrate the first two; they are VERY powerful tools.) These are useful for design inspiration, helpful hints, tips, methods, theory, and places to buy specialty parts. If you can think of any more pages to add, please contact me.

Google
eBay
SpudTech
SpudFiles
SpudWiki
Burnt Latke
NeoSpud
Cherry's Potato Cannons
Mark's Launcher Page
AdvancedSpuds
Antenna Launchers
McMaster-Carr (Materials)
BC Arms
SpudCom.com