Lines formed outside the Apple store in New York with customers eager to purchase the product, which is one of the most hotly anticipated devices since the iPhone was launched in 2007. The lines weren't as long as they were for the iPhone, but buyers seemed ecstatic after getting the iPad in their hands.

An instructor at New York University, Matthew Knell, waited in line for a few hours to purchase the device. He plans to use the it for entertainment and to read e-books to replace loads of print textbooks he otherwise carries.

"It offers the opportunity to mix music, movies and books in one good personal-sized package. It does a lot of things the laptops do well, and it has the opportunity to change the way we consume media," Knell said.

The iPads that went on sale Saturday include Wi-Fi, and are priced ranging from US$499 to $699, depending on storage capabilities, which range from 16GB to 64GB. Models becoming available later this month will include 3G mobile broadband, and will cost from $629 to $829.

The device should be available worldwide by April, Apple CEO Steve Jobs said during the device's launch event in late January.