I'm also transitioning to using it to integrate new knowledge. Clip to Evernote. Create flash-cards in Anki, and practice on my commute.
Basically, anything that I have to look up on StackOverflow.
E.g. os.path.relpath, -[NSString valueWithPointer:], -[NSString substringFromIndex:].
My loose heuristic is if I claim to be an X programmer, and some douche calls me out on an API call for language X in an interview, would I feel embarrassed saying I usually just look that up on Stack Overflow.