I had a Nokia 6111 when I first started on O2 (number was ported from
my old orange PAYG). A few weeks ago I upgraded to a 6550 slide. I
understand that if I want to use any video calling features or 3G data
I need a new SIM card. Will I be able to get a new SIM and keep this
number? Will it involve some sort of 'internal' number port to a new
SIM?

Cheers

Ian