I haven't experienced any guerilla marketing myself, but I have found a number of examples that makes me think, "why didn't I think of that?"
|Mall floor decal for Frontline Flea & Tick Spray|
Guerilla technique for the hit TV show The Sopranos
If this isn't a good way to get someone's attention in New York City then I don't know what is. This morbid image will strike anyone right away. It could offend someone easily but it really works with the show it's promoting. I love how at first you don't realize it's an advertisement until the arm leads you to the bumper sticker explaining its purpose.
McDonald's gets a huge standing-O from me. This is pure genius. What a good way to use already standing city structures to your advantage. This larger than life guerilla marketing tactic catches the eye of anyone walking by. Even the lady in the shot is amazed. I just love how the coffee pot is floating in midair. It's a fantastic illusion that kind of makes you think, "how'd they get that up there?"
Here are some other examples that I found:
|"Reserved for Drunk Drivers"|
|Ugly Betty Mall Poster|
|Yellow Pages Darts|
|"Free Air Guitar" 95.7 Rock Radio|