March brings South by Southwest Interactive, which means that some 25,000 entrepreneurs, marketers, journalists, and engineers will make their annual pilgrimage to Austin. Because the conference draws so many tech types together under one roof--and because both Twitter and Foursquare took off at previous festivals--SXSW has become the go-to destination for tech start-ups looking to make it big.

But conference buzz doesn't always lead to instant success. For instance, Highlight, a mobile app that lets you connect with people nearby, was one of the most hyped start-ups at SXSW last year. It failed to attract a large following after the event.

In other words, predicting the winners of SXSW is more art than science, but we'll hazard a few guesses. Here are four of the coolest start-ups heading south this year:

Leap Motion
Leap Motion might just have the must-see product demo at SXSW this year. The start-up developed a device, about the size of a flash drive, that lets you control your computer with hand gestures. Think Minority Report meets the Xbox Kinect--only cheaper, smaller, and more precise. The $80 controller--available for presale online--can track finger movements to up to one-hundredth of a millimeter. The San Francisco company, which launched in 2010, raised about $30 million in January, bringing its total funding to about $45 million. The company will begin shipping its first sensor in May.

Where to go: Leap Motion co-founders David Holz and Michael Buckwald are set to speak at the Austin Convention Center on March 9. It's the featured session in that time slot, so get there early if you want a good seat.

Memoto may be one of the most curious start-ups at SXSW this year. The Swedish company created a tiny "life-logging" camera, designed to be worn all day, every day to document the wearer's experiences. The device, which clips to a shirt collar or a lapel, takes two geotagged photos a minute. The photos can then be uploaded to a computer via a USB cable for sharing online. Memoto was one of 48 companies selected as finalists for this year's SXSW Innovative Accelerator awards.

Where to go: Memoto's CEO, Martin Källström, and his co-founders will demonstrate the product on March 11 at the SXSW Startup Village (a.k.a. the fourth floor of the Hilton across the street from the conference).

Eevzdrop is a bit like Instagram, but for sharing audio. The app lets users record a sound bite; add a location, text, and a photo; and share it with friends. Rommel Paraiso, CEO and co-founder of the Chicago-based company, is hoping to gain real traction among music bloggers and reviewers at the music portion of the festival.

Where to go: Check out Eevzdrop at the Startup Village, or email Paraiso for a private demo:

OUYA, a yet-to-be-launched video-game system, is expected to make its official debut at SXSW this year. An open-source competitor to Xbox and PlayStation, OUYA got its start on Kickstarter last year. Founder Julie Uhrman, a video-game industry veteran, reached her $950,000 funding goal in eight hours. The project fetched a total of $8.6 million, the second-highest amount ever raised on Kickstarter. Uhrman hired design guru Yves Behar, founder of fuseproject, to develop the console.

Where to go: Uhrman is a bound-to-be-talked-about keynote speaker. Catch her on March 11 at the Convention Center.


The SXSW Launching Pad

Twitter: It took off at SXSW 2007. Tweets tripled to 60,000 a day.

Foursquare: It launched at SXSW 2009. Months later, it had 60,000 users and $1.4 million in funding.


This article was updated on March 1, 2013 to reflect changes to Leap Motion's price and launch date.