Editor's note: The crowds did show up eventually Friday afternoon, as can be seen in the photo added below.
The 3G version of Apple's iPad goes on sale in the United States at 5 p.m. Friday, and so far, the crowds haven't begun queueing in San Francisco.
There have been reports of lines forming at a few stores on the East Coast. However, there isn't an expectation of throngs turning out for the first sale the way they did for the Wi-Fi version of the iPad earlier this month. (Update, 3 p.m. PT: at the Apple Store in Manhattan's Upper West Side in the minutes leading up to the 5 p.m. launch.)
Apple on Friday said its stores will be closed for an hour, starting at 4 p.m., to prepare for the device's launch. People who preordered an iPad 3G should receive their shipments starting Friday, too. Those who missed the preorder period will begin receiving their shipments by May 7, according to Apple's Web site.
Apple said it sold more than 300,000 Wi-Fi-only iPads when they went on sale April 3. Because of the higher-than-expected demand, Apple said it was forced tountil the end of May.
CNET's James Martin contributed to this report.