My Vario was locked to T-Mobile, but I searched the internet and found a free bit of software that unlocked it to all sim cards. I will try to find out the name of the software for you.
Alternatively, you can pay to have it unlocked (about �10). Most Towns usually have some market stall which offers this service.
Oh excellent!! this is good news -i'm desperate for a chunky phone I can't just wreck, but am currently tied into an 18 month contract with vodafone...