Gary, an aerobraking question for you.
http://groups.yahoo.com/group/planetary_sciences/message/682
Alex's Planetary Science group has a question about using the exospheres of the gas giants as a primary aerobraking mechanism. Do you have any pertinent comment - Alex or I can relay it to the Planetary Science group or you can join and post direct, but you'll have to wait 24 hours while Alex approves your membership (this keeps the trolls out).