Delta Air Lines passengers will soon be able to use in-flight Wi-Fi service on domestic flights. The carrier has partnered with Aircell, whose Gogo service will cost a flat fee of $9.95 or $12.95 for trips under or over three hours, respectively, and will allow connection of any Wi-Fi device such as laptops, smartphones and PDAs.

American Airlines and Virgin America both have announced testing of Aircell's Wi-Fi service on a limited number of flights, but Delta is making a big splash with an ambitious rollout to all its domestic fleet. Other carriers are watching the move closely and will likely follow suit. After all, Aircell's system is extremely light and relatively cheap to implement - thus has the potential to be a real profit center. Delta said it will roll out the Internet access beginning in the fall and complete the installation by the summer of 2009.

JetBlue Airways has also embarked on plans to roll out onboard connectivity but its system enables e-mail and text messaging only. Meanwhile, Southwest Airlines and Alaska Airlines are expected to test a satellite-based system by a company called Row 44 this summer.