Lenovo claims the IdeaCentre Q180 is one of the smallest HTPCs out there-- with a casing just 22mm thick packing a 2.13GHz Intel Atom dual-core processor, up to 4GB DDR3 RAM and either a 750GB HDD or 128GB SSD for storage.
A Radeon HD 6450A graphics card handles 1080p video output, with Blu-ray drive, 7.1 channel surround sound and DirectX 11 support. Video connections come through VGA and HDMi, as well as S/PDIF for HDTVs and sound systems.
A VESA mount allows one to fit the PC anywhere in the home, and it is also compatible with the Lenovo wireless handheld keyboard range via Bluetooth and wifi connections.