That audible gasp you just heard from the Internet? That was the reaction to Mark Zuckerburg's announcement that Facebook had purchased Instagram for $1 billion dollars.

In case you're not already one of the 30 million users of Instagram, here's the skinny: it's everyone's favorite, little photo sharing and social media service. Until recently it was only available on the iPhone, but last week it launched on Android as well.

I love Instagram. It's fast, compact, and if you want to upload a photo from your smartphone to any of your social networks, it does them all in one swoop. I have mine set up to post to Twitter, Facebook, Flickr, Tumblr, Posterous, and an email distro. Plus there a host of built-in filters to make your photos looks totally hip with no effort.

In his announcement Zuckerburg promised to leave Instagram alone, and to do their best to "learn" how to properly manage and cultivate a photo-based social network. I certainly hope that's true. I really don't want Instagram ruined like everything else Facebook touches.

Here's a gallery of my favorite Instagram photos.