While most still wait for their iPad 3Gs to arrive tomorrow, reader Robert S. was kind enough to send us the following screen shots of signing up for AT&T 3G service on his iPad 3G (he got his a day early -- lucky guy).
As you can see, you simply touch the Settings iPad app, tap on Cellular Data, enter your payment details, and boom! you're presented with a Cellular Data Account page which shows you your Cellular Data Plan account number, the status of your plan (how many days you have remaining), the billing period, and the abilities to add data or change your current plan and also add an international data plan.
Robert also notes that AT&T apparently assigns you a new mobile number for billing purposes.
We can imagine AT&T will be inundated with signups this weekend, so let's hope their servers and data towers are up to it.