A social messaging application called Twitter has taken SxSW by storm like nothing in recent memory. It seems like everyone in Austin is either Twittering, deconstructing the relevance of Twitter, building a Twitter enhancement, or wondering why the hell they didn’t have the idea first. It’s pretty clear that SxSW 2007 will bee seen as the moment where Twitter hit its tipping point.

If you’re not familiar with Twitter, it’s a web 2.0ish chat/SMS mashup that allows users to send quick messages to friends (or the world) from just about anywhere. Unlike traditional chat and SMS, Twitter seems to be more group based and messages have persistence. Your most recent twit becomes something of a short-term status for your entire life.

Twitter messages are the kind of thing most of us would never bother to put into a blog post. Unlike chat, they tend to be more like random messages to the universe — frequently with little or no discernible purpose.

The SXSW group is full of drunken one-liners documenting a fractal mosaic of the conference experience from thousands of different viewpoints. It’s a story of free beer, missed taxis, and broken toes.

Twitter is very much of this particular moment, both literally and figuratively. It’s succeeding right now because it conforms to so many the currently popular buzzwords. It’s mobile, social, and viral. It’s also proven to be a pretty effective way for many in attendance here to connect with friends and find interesting things to do.

Twitter’s exponential growth corresponds with what feels like exponential growth in SxSW conference attendance. The Interactive festival has reached its own tipping point this year. Unlike previous years the conference now sprawls across multiple floors of the Austin convention center. Sessions and hallways are so crowded that the traditional hallway banter between sessions has become more challenging. The people you’re interested in talking with are frequently on another floor, or the other side of the convention center altogether. In some ways its almost as if conference attendees have adopted Twitter as an ad hoc replacement for some of the lost (or at least damaged) socialization that has traditionally been such an important part of this event.

While SXSW is growing in size, it seems to be losing a little something in personality. It’s hard to tell whether or not Twitter will sustain the growth it’s experienced at SxSW, or whether its merely a temporary hack by the geekerati to replace some of what SxSW has lost to the masses. Some here are already speculating that Twitter may not survive the post-SxSW comedown.

If I were a betting man I’d probably wager that someone here will come up with something more compelling by this time next year. For now, though, Twitter is where it’s at.