Airlines: Mobile check-in and in-flight SMS.
A new check-in system from Sita, currently in testing, will enable travelers to pick seats from their mobile phone. An on-screen barcode will be issued as a boarding pass. Computing (2 Dec 2004, p. 12) quote Forrester research, who "... questions the technology's viability in the US, unless the Transport Security Administration agrees to accept barcodes displayed in cell phones for passage through security checkpoints."
Meanwhile, Travel Daily News reports that KLM are introducing SMS and e-mail services to some flights in February 2005. The system will be accessed via the seat-back and will cost US$2.50 per message sent or received.
Why can't passengers use their regular mobile phone? The BBC report that the current situation is due to the worry over interference with navigation, and also the fact that high-altitude jets simply cannot connect with ground-based mobile masts. This may all change: "American Airlines has experimented with a device called a 'picocell', a miniature receiver installed on an aircraft. Passengers use their existing phones, with the signal picked up on this picocell and then relayed to a satellite and then to the ground."