Product registration is now open:
http://www.samsung.com/us/mysamsung/...ductRegist2.do
Important: You have to select your device class to register.
Product group: Mobile
Category: Mobile Phones
Sub-Category: Sprint Phones
Model Name: SPH-I350
Model code: choose SPH-I350DLASPR (the middle one)
Serial Number: Enter your Hex serial number. When you tab out of the serial number field, if you entered it correctly, it will show your manufacture date.
The model code is important. I'm not sure what the first one is (SEP...) but the last one (SPH-I350DLSSPR) is for a Verizon branded model of this phone which doesn't exist on the market.