While the phrase consumer-generated content tends to bring to mind blogging, podcasts and YouTube mash-ups, there is also a groundswell amongst marketers trying to co-opt their customers' creativity. The goal is to engage them in a more intimate two-way interaction which unites them with the brand. For a mass brand, it seems that the problem will always be that they're only connecting with the most avid devotees and while there's nothing wrong with that, it's a lot of effort focussed on that small group of influencers.
In Germany, Adidas cleverly improved the methodology. They engaged the rabid consumers through an "invitation" to add graffiti to their posters (via a da Vinci quotation) but also transmitted a message to the passive consumer by incorporating that graffiti into new iterations of the poster that appeared within a matter of days. The whole process is illustrated in a slide show here.
There is a pretension to true interactivity with the few most active (or, perhaps,most destructive) people and while it's still literally wallpaper, its constant swift mutation is bound to be more engaging. One can argue about issues around encouraging graffiti and the blatant use of a tag that links to a shoe store (to be fair, I dont know if that was Adidas's idea or a smart entrpreneur co-opting their co-option). But, in contrast with those campaigns that impose their corporate graffiti on a neighbourhood and earn the wrath of the cynical consumer as exemplified by Sony PSP here, Adicolour was definitely part of the word on the street.