This interesting device, from Cydle, turns a an iTouch or iPhone into a television capable of receiving off-air television signals via the ATSC-Mobile standard. ;In addition to the antenna and off-air tuner, this device has a battery that powers its electronics and will charge the iTouch as well. This device should be out late in the first quarter of 2011.
A related post from awhile ago, http://www.viodi.tv/2008/04/28/mobile-video/