Smell is the sense most strongly associated with memory — and the least-used sense at the average gaming session.
Has anyone ever tried to use scent in their games? (You in the back, keep the jokes to a minimum…) Lighting a scented candle every time the party is in a particular city, striking a match, lighting a cigar — anything like that?
As corny as it sounds, it strikes me that this could be a pretty powerful technique for forming mnemonic associations at the gaming table. The major limitation seems like it would be the limited range of ways you can generate different smells.
Someone needs to invent a smell-o-gaming machine.