I regularly pick up turns of phrase from whatever book I happen to be reading at the moment, if they're used repeatedly in the book. However they tend to fade over time as I read other ones, so I don't know if that qualifies or not.
I'd have to say that the Complete Sherlock Holmes (which I checked out from my junior high school library so many consecutive times that the librarian tried to stop me from checking it out more, but had to concede that no one else was asking for it, and let me check it out several more times) massively broadened my vocabulary. It wasn't until some years later that I realized why others snickered when I would use the word "ejaculate" in conversation -- at the time, I figured it was just because it had four syllables.
