I'd like to introduce the Dell OptiPlex 9020 Micro PC to you. That there's the PC; that there's a coffee mug. It sits on a vertical base upright like the image there, or, can lay flat, or, can be mounted behind a monitor with a VESA mount kit.
The other day I replaced a business-class machine with one of these with a Win7 Pro install, an Intel i5, 8gb RAM, 125gb SSD configuration and it worked great. Supported dual monitors via VGA and Display Port, and, six USB ports - four on the back and two forward.
Since most of my practice leverages cloud, I tend to recommend thin and lightweight client computers like these for rapid, appliance-based deployments. In this case, I had to use a Windows computer for Windows domain participation and to run Windows-based software used by the firm. It took no time at all to access domain resources, Google Apps resources, and get this user back online quickly. And it's fast! All that processor, memory, and super fast solid-state hard disk makes for a very pleasant user experience; 6x faster than her last PC.
The Dell 9020 product worked pretty well and I'm likely to recommend it again to any small business leveraging cloud or server based products for storage, and, who must use Windows applications.