While searching for a link for my brother on building antennas for HDTV (you guys are all ready for the oncoming digital TV Apocalypse, aren't you?) I found this interesting link on an antenna which seems very good, and suitable for amateur construction. Seems like I could use some of the 12 gauge wire I used to make my Cheap Yagi to make this antenna in an hour or so. Might be a fun experiment, although since I live at the bottom of a rather narrow valley, I doubt it will render hdtv service tenable at my current location.
Addendum: Here's a link to the general dimensions for the single bay version. It's got two layers: he first has a pair of zig zag elements, and the "reflectors" are 100mm behind. Should be quite simple to fabricate.