Sadly, today's pick for most startling on-the-street advertising isn't a joke, though it sure seems like it. I must have missed that moment in the series when Sherlock Holmes expressed his passionate enthusiasm for taquitos. I always thought he was more of a Slurpee guy. I can almost see the advertisement: "It's elementary, my dear Watson. Slurpees taste GOOD."
(Hat tip to Chris Gebert—whose reflection makes an appearance in the photo—for spotting this outlandish bit of cross-promotion.)