Have a spare display sitting around that you want to turn into an (albeit limited) PC? You might consider picking up a Chromebox. The tiny low-powered machines, which run Google's Chrome OS, are best for basic productivity apps and content consumption, but if you don't need to do any complex processing, they might be a solid fit -- especially if you're on a very tight budget. Today, Acer announced a new model of its own, the Chromebox CXI. There's an Intel Celeron (Haswell) processor, a 16GB SSD, plenty of connectivity and support for two displays. One version includes 2GB of RAM and ships next month for $180, while a model with 4 gigs of RAM will run you $220. Both include a keyboard, mouse and mounting kit in the box.
Acer Chromebox CXI