I have tried this recently and has worked both times. If you definately would like an upgrade and are somewhat flexible with your plans, CO will let you take another flight (assuming First is already full on your scheduled flight) with some conditions.

For example, On a recent flight from Altanta to Neward I was schedules on a 6:45AM flight. Since I am only Bronze and using ELTS I called the night before to see about availablilty and they said that the 6:46 was full in first. I asked when the next flight was and they said that the 8:45 had 5 open seats. According to CO their policy is if you "miss" a flight, and check in within 2 hours after the departure, you can take the next flight with no penelty. This worked well for me and even got to sleep an hour later.

Many of you may know this but if you fly on restricted tickets and are not gold or platinum it is sometimes worth it.. Just my 2 cents.

This is true, but it all depends on availability. Altanta to Newark in the AM is great because they have lots of flights, about every hour or so.

I've often been booked on a sat morning early AM flight(atl to ewr), checked with the onepass folks before going to bed, discovered lots of seats on later flights and decided to sleep in a little later, never had a problem, never paid a penalty.

A few times when I checked in with the ETM's it gave me the option of switching to a later flight.

Great scoop!! Thanks for the info. I'm a Gold Elite, but even for me FC is full. I'll try a later departure the next time my schedule permits.

Both CO and HP permit stand by travel on day ticketed. This can be used to save money when on traveling on discounted tickets, I often will buy a ticket for a later flight when the fare I want is not available on the flight I want, as an Elite I get priority and usually travel on the flight I want.