Admittedly not my favorite type of inspiration, but I'll roll with it.
Ladies and Gentlemen, Socialization.
Making friends, making enemies, making acquaintances that secretly think you are just about the strangest organism they've ever had the displeasure of knowing, it's all the same. Interaction with other people and/or things. (And no, unfortunately, imaginary friends don't count.) This, indeed, is a source of inspiration. And it comes in a variety of forms.
Coffee Shop Writing
And other such public places where you sit down, work, and keep half an ear open. This is observing people that have nothing to do with you, giving you a unbiased look on the workings of socialization. Just be sure you don't look too much like a creeper.
Interacting with Friends
While it is a more biased look on life, at the same time it gives you a deeper understanding of it. Observe what your thinking, what your feeling, while you talk to people. Are you sincere? Are you a phony? If so, why? Writing about it.
Dorkzilla time here Monkeys, you need to pay attention to what's on TV, music and otherwise. Know the linguistics of it too. You'd be surprised how useful it is in shelling out your fictional world.
Bottom line, it's all about observation.
So observe observe observe! You never know where inspiration sparks.
THAT'SALLFOLKS! Enjoy this little photo!