Update 2: Hurry-Available dates and times are going very quickly!!!
Update: There is a .50 reservation fee. The fee is the same no matter how many free tickets are reserved at the same time, so 1 ticket or 100 tickets will be .50. You can purchase tickets for different trips at the same time from your shopping cart!
Use promo code: WIN2008
I checked random future dates for routes like Cleveland-Chicago, Los Angeles-S. Francisco, and Los Angeles-Las Vegas, and they all had free tickets available!!!
Thanks to S.B.S. for the tip!