Wasn't sure where to put this really...but chitchat sounded like a good home!
In a week's time I'll be heading to the US for a short holiday. I've just realized that my cell phone plan has now been cancelled, so need to figure out a new way to contact people. I had a quick chat with the people at O2, who said that it will cost a whopping £1.49 per minute to make a call in the US to a US number.

I'm wondering now:
A- Has anyone ever used their UK mobile with a US SIM card? This is looking like the cheapest option, but would mean I need to unlock my phone (I think?)
B- How would one go about unlocking a UK Mobile on O2 (It's a quad-band Palm Pixi Plus) And, if anyone knows the difference between unlocking/ unblocking/ jailbreaking, that would be great to know!
C- Would I be able to buy a SIM card in the airport (EWR)? I've only ever really seen these things at like Walmart or Target....I read on the EWR website that they have a mobile phone accessories shop, so maybe it would be worth ringing them to find out if they sell SIMs too.
D- Can anybody recommend a good PAYG SIM card to use in the US?? I'm pretty sure anything will be better than £1.49/minute!
Thanks so much in advance!! I feel completely clueless here!