I work for United and am based at IAH .. It is a big airport, and if your Ord flight is delayed it could be a run through the airport. Being the only flight toSTT that day ,United I could possibly hold flight for a few minutes. Just before you land inIAH, look at the Hemisphere Magazine in your back seat pocket. In the last few pages is a layout of IAH that shows gate locations. There is also an Airtran that goes to both C and E gates.