I have both a Continental and United card that have paid for several first class upgrades and or free tickets. It is a good value IF you are disciplined. I use my cards for everything and pay them off, so I am only socked with the annual fee. Since United and Continental merged I now only belong to the United program, however my Continental card still earns me points into the United program. They gave me 25000 miles after my first purchase and give me upgrade vouchers for domestic travel. They also gave me club passes this year, so the annual fee is trivial.
