Many moons ago, when I lived in colder climes, I used to ski. I enjoyed the daylights out of NASTAR racing in which we raced a slalom course against a time established by a national standard. (see www.NASTAR.com) I wonder if anyone has ever tried to run a time trial in the same manner.
Here's how I can envision it working. Lay out a course and get the local hotshot roadies to come race on it and use the fastest time as the standard. As in NASTAR ski racing, each rider is given a handicap based on his/her age. If you finish within a certain percentage of the standard you get a medal or certificate or some other such feel good trinket.