Also worth mentioning is to seek out other Star Alliance partners to get access to those same flights you might find on UA. For example, US Airways.

US Airways has their own card (Barclays) and the SPG card (AMEX) transfers 1:1 to US Airways. Comes in handy since UA miles are so useful and seem to be monopolized by Chase at the moment. Have to consider the banks and airline partners if you intend to get serious in the "game".

Happy reading.