I also am looking to use my Galaxy Tab in Europe. I know (or am pretty sure) that Verizon and Sprint will not work due to not being GSM. So it's between T-Mobile and AT&T. Now I have been with AT&T for a long time, have my Captivate through them, and are inclined to get the Tab from them. Also, AT&T lets you buy "blocks" of data for international use, like $25 for 25MB $60 for 50MB. Does T-Mobile have anything like this? The only thing I could find on their site for $15/MB, which is extremely ridiculous.