So I hacked of the key blade, hollowed out the plastic key head, and epoxied a flash drive inside.
Step 1: Parts, Supplies and Tools
1. Flash Drive
2. Junk Key.
1. Hack saw
2. Dremmel with milling bit.
Step 2: Cut Off the Key Blade
Step 3: Take Apart the Flash Drive
Carefully take apart the Flash Drive.
Step 4: Hollow Out the Key Head
Using the highest speed possible, I removed the material in the middle of the key head. This is tough work. In the head is the rest of the key blade (brass or steel), plastic and a microchip. Once the slot seems big enough I test fitted the flash drive.
Step 5: Insert the Flash Drive and Epoxy in Place
Insert the Flash Drive. Let cure.