Blood Drive: A moped rally
The Mosquito Fleet of Seattle, Washington holds a rally every year entitled Blood Drive in Seattle the first or second weekend of August. Moped Army members and non-members come from around the country to participate. In 2005 there was appoximately 70 bikes on the ride to Vashon Island.
No actual blood is donated to official organizations. But every year some blood (and some skin) is left on the street accidentally.