I love the board game Clue -- the logic appeals to my inner computer geek. And the Master Detective edition is even better, with additional suspects, rooms, and weapons to make things more interesting. I have little resistance to being drawn in when the situation presents itself.
So I was playing a game recently and all of a sudden it hit me that this was no ordinary game. A geocache had been hidden, and this game was telling me where! Here's how it went:
I played Mr Green. I'm pretty sure he didn't do it, but who knows? So on my first turn I made it to the Ballroom and called M. Brunette in for a visit. I suggested that he did it there with the rope. Disproved. Oh, well, it's only the first turn.
Next up was Mrs White, who entered the Kitchen and suggested that Miss Scarlett used the knife in commission of the crime in the kitchen. Also disproved. More info, but the game is young yet.
Col Mustard didn't fare much better: he called Mrs White over to the Dining Room and suggested she did it with the candlestick. This game is going to go on forever!
As people pondered Col Mustard's suggestion, Miss Scarlett made her move and and brought M. Brunette to the Hall. Perhaps he did it there with the revolver? But, no, M. Brunette could not have done it, as I had the card and showed it to disprove the suggestion.
The game went on, although I didn't pay much attention to it because at this point I looked back through my notes and realized where the cache had been hidden!
You're looking for a small camo thermos. Hint: it's not in the billiard room!

You can validate your puzzle solution with certitude.
[Certitude enabled 2/17/2012; verifications done prior to that date not included in attempt totals.]