Have a problem, trying to figure out what's going on... A little over a week ago I got my 3G. The day after I got it I signed up for the unlimited data plan without any hassles, got my confirmation email, etc. Just to test it out to make sure it was working I turned off the WiFi on the iPad and used the 3G to surf around the web a bit, everything was perfect. Well since I am mostly at home (WiFi network) I turned off the 3G and have been using the iPad exclusively on WiFi for about a week. Then yesterday I had to run some errands across town. Got on the metro, pulled out the iPad, turned on the 3G and... "no service." Figured maybe it was something to do with all the metal of the subway train, so waited til I arrived at my destination, got outside, sat down on a park bench... "no service." Went to 3 or 4 places all around Washington DC and its near suburbs, everywhere "no service." Finally got back home, and even at home (where it had worked perfectly fine a week ago)... "no service." Getting the same message today. I'm trying to figure out if it's an AT&T issue (doubtful, unless the entire greater Washington metro area has had its 3G network down for over 24 hours now...highly unlikely), a hardware issue (could some component in the iPad critical for the 3G somehow have broken?) or whether there is some setting that I am just missing. So to start with the latter, is there anything I need to be doing in the Settings besides simply turning on the "Settings --> Cellular Data" to "On"? I can hit the "Settings --> View Account" and log in correctly, everything seems fine there. Not really sure what "APN settings" is for, I assume just use my AT&T iPad login & password, yes? I'm perplexed. Help!