Aircraft computers use the Acars protocol to tell ground operations about their ID, flight number, position and other free text as entered by pilots. Using an airband scanner hooked up to the line-in, this software decodes and displays the information.
Harv's Hamshack Hack. A remaster of the KNOPPIX distro for Amateur Radio Operators (Hams) who have no prior experience with Linux. Provides a complete OS, software for hobby, web, and word tasks. All contained in an .iso file ready to burn to CD.