I just found out that there was a longish segment on the PBS evening NewsHour show on 4/28/03. The transcript includes Terence Smith summarizing the form this way:
Weblogs are public web sites characterized by brief, time-stamped entries in reverse chronology, often laced with edge and attitude. They customarily include hypertext -- links to other sites favored by the author -- and some now include still photos, video, and audio.
The story makes for a friendly introduction or overview.