If you're not on a contract currently you can just ask vodaphone to unlock it for free. Alternatively pay their early termination fee and unlock it. If you're pay to go, if you've spent 100 you can also ask for a free unlock.Well if you search on ebay there are unlocking services for barred phones - just ask the premium sellers around, they want your money so they should help you out. I saw offers like that on polish auction websites as well. This, or jailbreak. I am currently unlocking my phone cause I am absolutely sick of my carrier (seriously Vodafone in Ireland is beyond bad) and I hope I will have my phone unlocked no problem. It's like 30 euro but maybe cheaper/pricier depending on the carrier (I'd say try to find out to what carrier the phone is locked to).
Those premium carrier unlock services are pretty much fraudulent, they use contacts at the carriers to unlock phones. No guarantee that those actions aren't caught by the fraud prevention depts. and undone. Just FYI