Apple's iPad is now available for pre-order through the Apple Online Store. The company is also allowing customers to reserve iPads and pick them up at Apple Retail Stores.

Apple is promising free delivery to customers' doors on Saturday, April 3, or in-store availability between 9 a.m. and 3 p.m. the same day. In areas where Saturday delivery is not available, the company says delivery will happen on April 5.

Reservations are limited to two per customer.

Pricing starts at $499 for the 16GB Wi-Fi-only model. A 3G radio raises the cost to $629 and also adds a delivery delay: The company is promising 3G-equipped iPads in late April. The 32GB model lists for $599 and the 64GB model sells for $699, both of which cost $130 more with 3G capabilities.

For the latest Apple tablet news, opinion and conversation, be sure to check out InformationWeek's Special Report: Tablet Wars -- Can Apple Three-peat?

A data plan is extra. AT&T, Apple's only carrier partner at the moment, is offering two data plans: $30 per month with no contract or $15 for 250MB of data per month.

The continued availability of unlimited data plans was called into question recently when AT&T CEO Randall Stephenson said in an investor Webcast in early March that he expected the industry to move toward a metered pricing model, whereby heavy data users pay more than those who don't consume much data.

In an article in The Wall Street Journal earlier this week, Verizon CTO Anthony Melone echoed this sentiment.

Earlier this week, the Electronic Frontier Foundation slammed Apple for " acting as a jealous and arbitrary feudal lord" over its iPhone OS ecosystem and urged developers to demand better contractual terms from the company.

Analysts have yet to reach a consensus about the iPad's sales prospects in the first year, with numbers ranging from 1 million to 10 million units.