Terk Technologies have released the HDTVo, a compact outdoor HDTV antenna for city dwellers and for those who don't want a giant dish sticking out of their windows (or for their cranky landlords), and also don't have digital cable or satellite TV. The design uses a "highly directional log periodic antenna array in conjunction with a pair of curved elements that capture and focus HDTV signals toward the array."  In other words, it is designed to reject interference and focus the signals you want.  They promise outstanding UHV and VHF HDTV reception, and the small design can be flush-mounted or mast-mounted, so you can install the thing on your terrace, your wall, or in an attic.