Apple will be closing its retail stores in the U.S. Friday afternoon from 4-5PM to get ready for the launch of the 3G version of the iPad. Some folks who have pre-ordered ’em may receive them prior to this time.

The Wi-Fi + 3G models of iPad have a suggested retail price of $629 for the 16GB model, $729 for the 32GB model and $829 for the 64GB model. The iPad is sold in the US through the Apple Store (http://www.apple.com), Apple’s retail stores and select Apple Authorized Resellers.

AT&T offers an iPad data service for the Wi-Fi + 3G model. For US$14.99 per month, you get 250GB; $29.99 gets you unlimited storage. Data plans for iPad include access to more than 20,000 AT&T Wi-Fi Hot Spots nationwide at no additional cost.