AT&T will provide no-contract 3G service in the U.S., with a 250MB data plan costing $14.99 per month, and an unlimited plan costing $29.99. International deals for 3G services should be in place by June or July, the company has said.

The iPad has been called a supersized iPod Touch, with a 9.7-inch touchscreen and an on-screen keyboard for typing. The device runs on Apple's A4 chip and can play back 720p high-definition video. Apple's iWork productivity application is included for those who wish to create documents, spreadsheets or presentations.

The iPad was declared a success even prior to retail launch. Apple watchers suggest that hundreds of thousands of customers have already preordered the device from . Market research firm iSuppli on Friday estimated that close to seven million iPads would ship by the end of the year.

The device has received positive reviews for its long battery life, multimedia capabilities and e-book reading features. Analysts have also said the iPad could impact content distribution and spawn new ways to deliver video, news and e-books with specialized interfaces. The device also excels in Internet and surfing, which could affect the sales of devices like netbooks, analysts said.

However, some potential customers , that the iPad has drawbacks, including the lack of a video camera, USB ports and support for Flash, which enables video on the Internet.