Hey guys, I'm researching options to switch to a later flight for a upcoming trip and I'd really appreciate any help.

I know US airways has a MoveUp program to fly an earlier flight, is it possible to do the same for a later flight? The other option is showing up about half an hour after my scheduled flight and hope they'll put me on the next flight. Would it be too risky? I'm an AA Plat if that makes any difference =\

Thanks in advance!