Just registered on FAA.GOV Took about 10 minutes. Didn't ask for any type of description, serial number. Just told me the rules/guidelines and wanted name, phone and address.
Had to create an FAA.GOV login (that took the longest since I had to check my email and click "verify")
Since I'm just a hobbyist/recreational operator I was very pleased with the simplicity of this process. I printed out my FAA certificate and I'll probably keep that in my Phantom case to be ready if I need it (you can also just show the electronic email of your certificate if law enforcement asks).
Happy flying!
Tom (tcg)
