I have never paid attention to my cellular data use because I still have a grandfathered-in unlimited AT&T data plan. Now I'm interested, because I bought a Verizon Galaxy Tab and feel plagued by impending overages every time I turn it on. So I navigated the infuriating complex process of finding historical data usage on AT&T and found on that in the last 6 months the MOST data I've used in a a month was about 500 MB. I feel like I'm on the phone ALL THE TIME, but I don't stream video over 3G, and evidently e-mails and Twitter just don't take much bandwidth. Good to know. Now I can use my tablet freely and fearlessly.