My baseline "techie" criteria is the availability of a screenshot utility. Only the Kindle and the iLiad have one. The developers of the Kindle software,
lab126, are clearly techies and have designed a very clean interface to the device. Lab126 also added many more features (like the screenshot utility) than are exposed in the documentation, but so far I am not aware of any hacks to the actual software. One I would really like to see is a method to replace the default font.