If I register my sprint phone on sprint.com as MY SPRINT- does this cost money...

...and add to my bill? I want to find out what kind of plan I have, because my phone is a gift- and I'm not sure if by doing this registration is going to add more money to the bill--- does anyone know what this does??

It doesnt cost anything! I have sprint phone and we go online all the time to either pay it or to check our minutes. there are all kinds of things you can do online! you can upgrade, buy ringtones, and other things!