From the UKSEDS mailing list:-

The Space Generation Advisory Council (SGAC) announces an international youth technical paper competition to develop unique and innovative concepts for how to deflect an asteroid or comet that could impact the Earth. Financial support for this competition is provided by Northrop Grumman Corporation, Lockheed Martin Corporation, SpaceWorks Commercial, and The Planetary Society.

The competition calls for individuals or teams under 33 years of age to write and submit a 3-10 page original technical paper on their innovative concept for asteroid mitigation.

The 1st place award is a trip to present the winning paper at this year's Space Generation
Congress (SGC) and International Astronautical Congress (IAC) which take place in Glasgow, Scotland from late September until early October 2008. The 2nd place award is a trip to present at the SGC. Entries are due on 09 June 2008 and winners will be announced on 30 June 2008, the 100th anniversary of the Tunguska Event, the largest asteroid/comet impact event in Earth's recent history.

For more rules, submission information, and a press release please visit:
http://www.spacegeneration.org/asteroid

A flyer can be found here:
http://www.spacegeneration.org/files/SGAC_Move_An_Asteroid_2008.pdf