Exchange ideas about something

Usage examples of compare notes.

Getting me and Giraud together someday and letting us compare notes.

I've no one with whom to compare notes as to whether this makes things rougher, though it massages my ego to think that the mark of the one makes the other more difficult.

You talk, you send him a fax containing instructions and you compare notes.

They stayed at Langley and he saw them as often as he could on his trips back east to compare notes with men who were working on the reentry problem there.