A few months ago I bought a WeTab from these people http://wetab.mobi/en/
, and it rocks. I don't know if it's already shipped to the U.S.A., as I'm in Europe, but the specs look really good: 2 USB ports, 1 mini HDMI, the usual audio out jack, and a proprietary port (for a dock) on the bottom, but unused at the moment (the company hadn't produced a dock yet).
It runs a WeTabOS, which is basically MeeGo + a graphical interface known as 4tiito, and that OS can easily be replaced by whichever flavour of GNU/Linux you'd like (MeeGo, Ubuntu,
...), and I think someone could also try cramming windows on the SSD. The processor is an Intel N450 at 1.66Ghz, with 1Go of DDR2 RAM. There's also a webcam, a SIM port... Basically everything you would need. At less than the price of an iPad (I paid mine about 460 euros, while the iPad here is 499 euros).