Gregory's ServerThis is a fully functional 7MHz 80186 DOS machine, running MSDOS 5.0, with full CGA graphics support. It runs off of two AA batteries. Apparently for weeks. While constantly powering a RAM disk. I have been using this thing fairly heavily since Wednesday, including large serial file transfers that took well over an hour of constant, sustained use. Battery is still at 7/8 full.
The thing I didn't quite realize until I had the thing in my hands is that it is a _very_ full-featured PDA, with a _ton_ of useful software built into ROM, and a multitasking shell with convenient app-switching hotkeys. Everything you'd expect on a modern smartphone is there - calendar, alarms / reminders, TODO list, contact management, stopwatch...