The Google Maps team has a Google Trike Special Collections Poll and they want your ideas on where to send the Google Trike. The Google Trike is a three wheeler with the Google Maps Streetview Camera so they can collect images of pedestrian malls and trails that are not accessible by car. Google mechanical engineer Dan Ratner is a mountain biker. Like many good ideas, the idea of a Google Streetview trike came while Dan was mountain biking.
I've never seen the Google Trike but some people I know have seen it in action in the South Bay collecting local bike path info for inclusion in Google Maps. Interestingly, the Bay Trail in Shoreline Park immediately adjacent to the Googleplex in Mountain View, CA doesn't have Streetview available (yet).