The Odroids in general are absolutely awesome and the Odroid U2 is even more so. Only 70mm on side with a Quad core 1.7GHZSamsumg Exynos 4412 Prime, 2GB RAM.
A full sized RJ45 10/100 NIC and 2 USB ports just finish off the micro HDMI and Audio out, USB OTG etc etc,. The device even comes with a microphone on PCB!
You can no finish the ensemble with a really nice range of cases
Available from this Ebay Store
They even come with an Assembly video :