The YC companies do outstanding elevator pitches in 5 or 6 minutes. The best I have seen anywhere. Pitches to VCs are typically 30 minutes plus time for questions...but their minds are usually made up after about 5 minutes.

In New Hampshire they have an interesting twist on the elevator pitch. They call it Peak Pitch. It is done in the winter at a ski area. The organizer pairs startups with investors and they get to pitch on the ski lift to the top of the mountain. Pretty cool.