Back in the days of its founding, Apple championed hobbyists and experimenters, even including circuit board schematics with the Apple ][+ to help people who wanted to tinker with the electronics. Not so now. Cory Doctorow (brilliant guy, read his Disneyland sci-fi novel) recently blogged about how Apple has switched its loyalty to the DRM-and-eternal-copyright crowd, and like the iPhone, the iPad reflects this. Consequently, the common temptation to covet an iPad is an evil one.
I like my Android phone (a Motorola Droid from Verizon) except for the PHONE part, the one thing it does poorly. Every other function, I adore. Also I'd like a bigger keyboard and screen, maybe Kindle size. So: Android tablet with bigger keyboard and screen, and no phone (therefore no messy dependency on mobile carriers).
I wouldn't want to try to build a tablet from scratch, but the Touch Book from AlwaysInnovating looks good. The tablet piece (sans keyboard, which makes it a netbook) is $300, loaded with their custom Linux OS. The OS can be replaced with Ubuntu, Android, Chrome, etc. An SD card makes it easy to get apps and files onto and off the tablet. There's a wiki to help developers get up to speed.
In another video, the inventor shows how to enable route tracking on Google Maps by popping off the back cover and plugging a GPS receiver into an internal USB connector. I am currently between jobs, but this is going on my shopping list for later.