Sorry that I found this thread a little late, but some info about United
Good luck! hope that it works out for you
- reservations can be cancelled within 24 hours of booking with no penalty
- above may not apply to bookings made via a 3rd party site
- United has same day confirmed standby for $25 - can be confirrmed within 4 hours of new flight. Check out their website for more details. You may be able to get on the later flight - having status with them does help on an airport standby list, but you can do the confirmed standby over the phone
Good luck! hope that it works out for you