The best gamification ideas usually come from just outside the traditional game space (and typically not from gamification 'experts' who are too busy adding badges and points to everything under the sun). The latest blockbuster idea, which could easily be adapted for some really interesting game mechanics, is Pinterest.
If you've heard the name, but haven't delved into it, it's a social media site/tool, allowing users to "pin" things they find online, usually images, to a themed collection, easily viewed and shared by others. The company describes itself as follows: "Pinterest is a virtual pinboard. Pinterest allows you to organize and share all the beautiful things you find on the web. You can browse pinboards created by other people to discover new things and get inspiration from people who share your interests."
Sounds like pretty much any other social networking tool or site, but somehow this particular one has exploded in popularity over the past few months, after launching quietly in 2010. I think this particular implementation works on two levels. One, it's primarily visual -- you're literally browsing scrapbooks of interesting things (a bit like a good Tumblr blog, in a way). Second, it appeals primarily to women, who make up the majority of social and casual game players (and should therefore be a key target for anyone interested in gamification).
Variations on the theme are already popping up. AllThingsD notes the recent launch of Mulu, which it describes as "a Pinterest-like e-commerce site that helps users generate money for their favorite causes." There's not a strong game element to that particular implementation, but it does have a points system, as well as a user-driven recommendation system.
The challenge is to develop a more game-centric version of this really interesting form of visual product communication. Could websurfers pin (or thumbtack, glue, etc.) their favorite products or uses from a brand or company to a shared virtual space, or perhaps their favorite scenes and characters from a film or television show?
If you've got other ideas for Pinterest-like game mechanics, I'd love to hear about them in the comments section below.