Google map and GPS in T-Mobile cellphone in Europe?

Hi,

I have T-Mobile GSM phone with built-in GPS. I have data plan. I am planning to travel to Europe (UK, France and Italy) in the summer. Here is my question:

Does anybody know if I can use the Google map or Google navigation system over there, free of charge? I tried to google this information but did not find the answers.

Thanks,

Xiong