The Sandia STX 165 is a small, light weight Mode C transponder designed to fit a ½ 3ATI instrument hole, leaving space in your TRIKE. The size of a dollar bill. The STS 165 features a built-in 35K foot encoder simplifying...
iPad Pilot News-- Lots on info on the iPad & apps (since it's Sporty's Shop link, I put it in "The Market)
"Tips, Tricks & News for Pilots flying with iPads and other pads"
http://ipadpilotnews.com/