I did not want to port as I expected start-up issues and knew about the trouble they were having with uninformed people that don;t want cell phone towers near schools (lowest radiation is below the tower - please install them at schools!). Also I have a spare phone so will keep both VF and 2D numbers for now.
When the on-line self-help was still available, I've picked the option to change my number and typed in the same number as my VF SIM but with 0220 instead of 0210. The number was still available so I took it. So now my VF number and my 2D number is identical except for the 3rd digit.
If I ported the number the VF SIM would have become useless and the 2D SIM would get the 0210 number, but I wanted to have a new number and just wanted to make it easy for everyone to remember.
When you receive the envelope in the mail you get a shrink wrapped SIM holder inside which is the same as if you bought it at the shops. The SIM holder has a label on the back with your PUK and mobile number and SIM card number. If you threw away the SIM holder without reading the label (i.e. don't have the PUK any more) then don't worry, (eventually) when you log onto the web site it will display your PUK. Very nice, you don't have to remember it!