If there’s one lesson that social media has taught companies it’s that they can no longer broadcast their messages to customers. Over the past few years, brands have opened up the channels for two-way conversations that let customers engage with them. Now, marketers are providing customers with the tools to co-create and place themselves in the brand, creating a truly immersive content experience.

Hang out with the Sex and the City gang

To promote the opening of Sex and the City 2 this summer, HP set up a photo booth in the Eaton Centre in downtown Toronto. Fans posed in front of a green screen to have their digital photos taken, which were then super-imposed onto the film’s poster as if they were one of the girls.

Participants received a printout of the photo on the spot. They were also given a card with a personal code and Web address that lead to a Facebook page where they could download a high resolution version.

The tie-in makes sense when you know that HP and fashion designer Vivienne Tam worked together to create a beautiful special edition notebook that provided a great – though controversial­– product placement opportunity for HP.

Mad Men Yourself

Last year, to promote the beginning of Mad Men’s third season, fans of the critically acclaimed AMC series were able to go online and create 1960s-style avatars of themselves with the wildly popular online application Mad Men Yourself.

To keep things fresh this year, the application offers new clothing, new accessories and new backgrounds. Fans can now share their creations on both Facebook and Twitter as well.

In another new twist, Banana Republic has sponsored a contest where fans can submit a photo of themselves in Mad Men-style outfits to win a walk-on role in Season 5. This ties in with their line of retro fashions and fantastic style guide which instructs customers on how to pull off that 60s look.

Design a Chiquita sticker

Who isn’t familiar with the little yellow and blue Chiquita banana sticker?

You have to give the company credit for being able to brand a simple piece of fruit. With their most recent promotion, Chiquita Brands is inviting consumers to visit Eat a Chiquita.com and put their own stamp on the classic sticker. Eighteen winners of the Chiquita Banana Sticker Design Contest will have their design featured on millions of slippery peels.

Not a graphic designer? Not a problem. Those of us who are not artistically inclined can participate in the fun by uploading our designs at the Zazzle store and creating our own custom gear. Kudos to Chiquita for maintaining its iconic brand for over 50 years – and for daring to try something new.

Co-creation at its trashy best

If you’re a fan of the MTV reality show Jersey Shore you can Jersey Shore Yourself with a silly application that transforms both guys and gals into a so-called “Guido” or “Guidette.”

Whatever you think of the show, this is a fabulous application that caters to its target audience. It’s tacky and trashy, but that’s the point.

The Fun Factor

These four examples show that co-creation marketing apps can work for a wide range of products and demographics. For brands, it’s a great, relatively cheap way to engage customers and earn some buzz. For the rest of us, it’s just a whole lot of fun!