Roku today unveiled the Roku Streaming Stick, a wireless device about the size of a standard USB flash drive that will plug into a TV to instantly transform it into a Smart TV.

The Roku Streaming Stick will feature built-in WiFi, processor, memory and software to deliver Roku's collection of streaming entertainment.

The device will not require any cables or a separate power source, and will be controlled by the TV remote. Like Roku players, it will deliver more than 400 channels found on the Roku platform today and will benefit from regular, free software updates and channel enhancements.

The Roku Streaming Stick will be available in the second half of 2012. It will be undled with a TV in retail or sold separately for consumers to use with their own TVs.

The streaming stick is expected to sell for $50 to $100. Electronics retailer Best Buy Co. plans to include the streaming stick in a line of TVs bearing its in-store brand, Insignia.

Roku's streaming stick will only work on televisions that have mobile high-definition links. It will plug into MHL-enabled HDMI ports on TVs. MHL is a new standard that uses the HDMI connector on TVs to deliver power and other critical elements for the streaming experience. MHL is currently adopted by nearly 100 hardware and manufacturing vendors including Nokia Corporation; Samsung Electronics Co., Ltd.; Silicon Image, Inc.; Sony Corporation; and Toshiba Corporation, who are the joint founders of the MHL Consortium.