You might also want to check out <a href="http://www.londontransport.co.uk/tfl/ftt_visitor.shtml" target="_blank">http://www.londontransport.co.uk/tfl/ftt_visitor.shtml</A> for details on visitor railcards for London. They will often include unlimited 1/2 day use of the tube and busses and the trip to / from Gatwick. The Gatwick trip would not be on the Express but on the normal trains ( about 10 mins longer ) but the prices are more sensible if you can't get the discount. Also the card would allow you to get to LHR as I believe that the ARN flights arrive there if you are going to meet your buddy.