The South by Southwest Conference and Music Festival has kicked off in Austin, Tex., and the annual “Woodstock for geeks” comes with its normal dose of big, big buzz.

The app that’s been flagged as the one to watch this year is Highlight, an iOS-only app that hooks into users’ Facebook accounts to let them find others who’ve installed the app. According to the developer Math Camp, the app is meant to give you a “sixth sense” about the world around you.

Highlight runs in the background, but sends users’ push alerts when the app finds other users in their general area. You can click on the names of other Highlight users, and check out their public Facebook profiles, including basic information, photos as well as Twitter accounts. You can make the information public. Those who are worried about battery life should know that the app requires constant access to location data, which can be a serious drain on power.

Other apps that are expected to break out this year, Mashable reported, include photo app Pixable, local-based Q&A app Localmind and Sonar, an app that uses public data from several different social networks — Facebook, Foursquare, Twitter and LinkedIn— to tell you who’s posting nearby.

This year’s election is also said to be a big trend at this year’s conference, the Wall Street Journal reported, with startups targeting campaigners and lobbyists and trying to get them to jump on the mobile and social bandwagon.

Highlight, a location-based social networking app, is expected to be the breakout app of SXSW

Related stories:

As digital, film and music worlds gather for SXSW media zoo, ‘convergence’ is annual buzz word

South by Southwest: Social media startups will have to share spotlight

For tablet computer visionary Roger Fidler, a lot of what-ifs