Great examples of Guerilla marketing

First things first, exactly what is guerrilla marketing? The term now covers a plethora of different marketing techniques but I rather like Marketing Terms' definition, which says "unconventional marketing intended to get maximum results for minimal resources." Now, doesn't that sound like a great approach for cash strapped online businesses?

Take the magazine FHM, who projected a 60-foot high image of Gail Porter's backside onto the Houses of Parliament to promote its 1999 poll to find the world's sexiest women. Then there was IBM who employed a graffiti artist to paint pavements and walls in San Francisco and Chicago with the words 'Peace, love and Linux'. The site About.com sent out fake hitchhikers onto Highway 101 in the States to give out promotional masks to any kind driver that stopped to pick them up. These campaigns all focus on creating a buzz around a product or service; it's then passed on by word of mouth as people talk about in pubs.