Sim Free Mobile

OK, there is one pay as you go T-Mobile phone in the United Kingdom that I really like (LG Shine) and I live in the United States. I was wondering if I could buy the pay as you go phone in the UK and then put in a pay as you go T-Mobile Sim card from the USA in the phone?

I cant wait until I qualify to go to the UK for my job!! How is it over there.