<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by oliver2002:
look at the load factor of the particular earlier flight you would like to take using seatmap.com and then approach the gate agent of the earlier flight asking nicely if you could take the flight. If you have no luggage and there is space you will get the seat with 99% surity. Always works for me!
Regards Oliver</font>
Is your 99% figure your own experience or is it based on some statistic? I know loads of people who are not allowed a standby or change simply because their fare doesn't allow it. Some airports have a very strict no-change policy, LHR's transfer desk is one of them.