The Palm Pre developer code has been discovered hidden inside, and is available from the launcher screen on your Palm Pre handset.
All you need to do is type in the phrase “upupdowndownleftrightleftrightbastart” which is the infamous Contra/Konami code and then delivers the hidden application “Developer Mode Enabler.”
Apparently it’s used to connect the Palm pre to a machine running Palm’s Mojo SDK for webOS, and we have a video which you can locate below that shows you just how to access the mode so hit it up and have a go.