Fender's Mod Shop lets you customize a new guitar on the web
It's like Moto Maker or Nike iD, but for 6-strings and basses.
Make your own accessories for the Steam controller
Valve has uploaded the CAD files for its gamepad with the hopes that you'll make custom accessories for it.
How It Stacks Up
Doctor Who TARDIS PC
iMac 24-inch (mid 2007)