While larger voting sites such as Digg and recently-released Yahoo Buzz keep their properties closely guarded, Reddit is taking the exact opposite approach, hoping to capitalize on its 300 percent growth since May.

Taking dead aim at its competitors, reddit now allows users - and publishers - to fully customize their own reddit communities. You can modify the CSS and use custom CNAMEs. Style the community, the logos, and point your own domain to your new, custom community. This could be a fantastic way to really engage your site visitors and have them engage with your site and your brand - even if you have to endure some third-party advertising on your custom voting site.

Depending on the success of the reddit experiment, we could see many more social networking/voting sites start to open up to private use. Revenue shares, third-party app inclusion ... Mixx, are you listening?

As an extra bonus to get started, reddit is running a contest for custom communities - grow the largest audience in one month and get a free Macbook Air.