Figured I'd try this here before dealing with craigslist or ebay. I've got a barely-used Android powered Viewsonic gTablet here that I don't think I actually want. The stock software is non-optimal and has no google apps or android market. It will run the new Amazon appstore, though, and it will run any app you can sideload from a .apk file. It has fairly powerful hardware, and there is a range of third party custom roms which can be flashed on it. It is also pretty much impossible to brick, since it's practically a dev kit packaged as a consumer product.
It's truely awesome for playing Angry Birds
I paid $349, looking for $300 or best offer.
EDIT - Traded this for a ToughBook on Wednesday.