In this overview of in-flight Internet capabilities，we take a look at what various airlines say they'll be offering to their customers，which companies are building networks，and when we can expect to get full Web connections on planes.
　　With the announcement Friday morning that JetBlue will be teaming up with Research in Motion and Yahoo to provide free e-mail and instant messaging on its flights，there are now at least four airlines with announced plans to experiment with in-flight broadband connectivity.
　　In this overview of in-flight Internet capabilities，we take a look at what various airlines say they'll be offering to their customers in the future，which companies are building their networks， and when we can expect to get full Web connections during those long cross-country flights.
　　American Airlines What they'll be offering：Nationwide in-flight broadband Internet access that extends from the coast to coast. American Airlines passengers will be able to connect to the Web during their flights using any device that has 802.11a/b/g Wi-Fi capabilities.
　　When it will be offered：American Airlines began testingBoeing 767-200 aircraft in August. The goal is to provide broadband service to all passengers starting in 2008. Wi-Fi capabilities on its fleet of
　　Who's building out the network：Aircell，a global airline telecom provider based in Itasca， Ill. Last year，bidding company and Aircell affiliate AC BidCowon the rights to 3-MHz on the 800-MHz spectrum to deliver Wi-Fi connection to airlines. AirCell first demonstrated in-flight WLAN capabilities in 2005.
　　Alaska Airlines What they'll be offering：A satellite-based 802.11b/g Wi-Fi connection for any laptops，smart phones and PDAs. These devices，says Alaska Airlines，will have access to the Internet，e-mail and VPNs，as well as stored in-flight entertainment. The in-flight system will connect to a satellite through an antenna placed atop the aircraft.
　　When it will be offered：The airline is still testing the Wi-Fi connection on its Boeing 737 aircraft. Ideally，the company hopes to have Wi-Fi connections on all 144 of its planes up and running by spring 2008.
　　Who's building the network：Row 44，a Westlake Village，Calif.-based airline telecom provider，which says it can offer in-flight downlink speeds of 81Mbps and uplink speeds of 1.6 Mbps. Because Row 44's system uses satellite technology，says the company，it will not be limited by international borders and will be available to planes throughout the North American continent. In addition to its Wi-Fi connection services，Row 44 is planning to roll out in-flight entertainment services，such as more than 100 channels of live television.
　　Virgin America What they're offering：Air-to-ground broadband Internet connection for 802.11a/b/g Wi-Fi enabled devices. Additionally，the airline's Red Inflight Entertainment network will allow customers to use a wide variety of instant messaging services on their seatbacks， including MSN messenger，Google talk，Yahoo！messenger，Skype and AIM.
　　When it will be offered：Virgin America first announced its in-flight broadband service plan in September，and the company hopes to have its all of its planes connected "sometime in 2008."
　　Who's building the network：Virgin America will be the second major U.S. airline to employ Aircell to build its in-flight network.
　　JetBlue What they're offering：Currently，the airline is running a trial that will give passengers free e-mail and instant-messaging service on one of its Airbus A320 planes starting on Dec. 11. Run through a partnership between JetBlue，Yahoo！and Research in Motion，the trial will allow passengers with Yahoo！e-mail accounts，as well as Blackberry users，to access e-mail and send instant messages. Blackberry users will have to connect to the network through Wi-Fi，however， as the FCC doesn't allow mobile calls to take place on planes.
　　When it will be offered：If the trial goes well，JetBlue is expected to begin working toward giving its customers full Wi-Fi enabled Internet access some time over the next year.
　　Who's building the network：LiveTV，a wholly owned subsidiary of JetBlue that won rights to 1 MHz of the 800-MHz spectrum last year.