This little pewter thimble is available for £3.00 (US$5.86), plus S/H, through Cluedunnit, a British website that specializes in murder parties. They have downloadable murders and "Box Murders" (parties-in-a-box with the clues and everything) for the do-it-yourselfer (party-giver, not murderer). They also host murder parties which can be bare-bones affairs or extravagant weekends for 25–100 of your nearest and dearest. They don't list prices for the parties, but I'm pretty certain I can just about afford the thimble.
Their pewter mementos all feature Sherlock Holmes.