Originally Posted by darrvao777

Yes, you set up the gift registry for yourself (I believe you need to be logged in for this to work). Then sign out or access the United site from a different browser and search for your registry by name. You'll be given the option to contribute with your AMEX Platinum card

Just did it myself last night, $200 in one transaction under gift registry. Showing up as a pending charge under the category "Travel - Airline". I've heard that's usually a bad sign for getting reimbursed but will keep following and update you all.