Geeze, what a lot of fuss and laughter about a basically sound idea.

The Yahoo article doesn't actually say how the airbags are to be used, but the New Scientist article they reference, at http://www.newscientist.com/news/news.jsp?id=ns99992730 makes things a little clearer. The idea is to use the airbag as a cushion between the near-earth object and ordinary rocket thrusters. If you give the object a little nudge early enough, and it doesn't disintegrate, you can alter its course enough to avoid the Earth.

The 49'th post on Yahoo's message board points to Burchard's actual proposal at http://abob.libs.uga.edu/bobk/ccc/cc081902.html

Don't judge someone insane based on what you read on Yahoo!