Hi - my girlfriend and I live in different cities (SEA and STL). Though we visit each other quite often - it'd be nice if we could also visit other cities together. We have tried in the past to find good deals to various cities but it's a lot of work. Are there any websites that would make this easier?

ie something that would say "right now, there are unusually low airfare from SEA and STL to SFO for this weekend". Or something like that.

Does that make sense?