The Lenovo Ideacentre Stick 300 is only 100 x 38 x 15 mm (3.94 x 1.5 x 0.59 inches) yet packs a full Windows PC inside. This includes an Intel Atom processor (Baytrail), 2GB of RAM, 32GB of storage, SD card reader, HDMI, and a microUSB 2.0 port. It has Wi-Fi b/g/n for connectivity and Bluetooth 4.0 for use with wireless peripherals. Due to the lack of ports Bluetooth will likely be needed for connecting a keyboard and mouse.
Simply plug the Ideacentre Stick 300 into the TV or monitor, add a wireless keyboard and mouse, and you have a full desktop PC for entertainment or work. This is aided by the included 3-month trial for Microsoft Office 365.
