Yeah, I get bored of sport conversations as well. I either do the "Cool, cool" line as Franco said without asking any questions, or if there is someone there that also looks bored, I talk with him/her about a different topic. If I'm in a fowl mood (rare) and stuck with 2 guys that are enamored in a conversation that I could care less about, then I have just gotten up to get a drink, go to the bathroom, or even talk to someone else. Generally, when you come back, the topic has died a little, or when they are looking at you as you're returning to your seat, you can bring up something like, "Man, I was just talking to this guy/girl, and..." or "Man, that bathroom was filthy..." or whatever, and it kind of kills the topic. Then just swiftly ask about something else.