Twestival - Twitter Festival.
1st Twestival Sep 2008 - Amanda Rose - an Canadian entrepreneur and some social media graduates in London started an event to raise money for charity and social cause. And collected donations and canned food for charity The Connection for the homeless. The event which was intended for 30-40 people ended up with a waiting list and all 250 attendees wearing @name stickers to identify themselves to others they had met online.
12 Feb 2009 - 202 cities with 1,000 volunteers and 10,000 people participated globally and raised over $250k through these events and online donations for Charity Water, resulting in 55 wells for more than 17,000 people served in Uganda, Ethiopia, and India.
2nd Twestival Sep 2009 "Twestival Local" - aimed to support a local cause on one day during weekends of 10-13 September 2009. It is hoped that it will raise $400,000.
"The aim is to give people a chance to feel they are contributing to a larger social initiative, but bring the cause a little closer to home." - Twestival Local
So Get Involved and volunteer in your city