SXSWi party wars: Foursquare vs. Gowalla (photos)

Foursquare and Gowalla, two of the most-hyped companies at this year's South by Southwest Interactive Festival (SXSWi) in Austin, Texas, are pretty tough rivals: both of them want to own the hot "geolocation" market, the big new thing in social networking.

And at SXSWi, both companies were throwing parties. On the same night. Around the corner from one another.

On Sunday, a design firm called Jess3 decided to get cheeky by sticking up posters around Austin for "The Geolocal Showdown," pitting the two Monday parties against one another like a boxing match. The poster depicts Foursquare co-founders Dennis Crowley and Naveen Selvadurai as "The Two-Headed Monster," and Gowalla CEO Josh Williams as "The Ultimate Underdog."

One thing was for sure--these parties were going to be packed. The line for the Foursquare party, which was held in conjunction with Brizzly, Katalyst, Stickybits, and a handful of other start-up partners, began before the doors had opened, and eager partygoers lobbied to get in on a VIP list to beat the crowds.

The Foursquare party easily filled up the Cedar Street Courtyard, a large bi-level bar in downtown Austin. It didn't help that the mostly-outdoors venue grew even more crowded when it began to rain and guests packed into the smaller indoor spaces.

Holding court in the Foursquare party's exclusive VIP section was none other than actor turned digital media mogul Ashton Kutcher. (He's standing next to the pole in the dark shirt.)

Around the corner at a bar called the Belmont, Foursquare rival Gowalla was throwing a party of its own. With a "tiki room" theme, the mai tais were flowing and the labyrinthine bar was packed with partygoers.

Foursquare might've had Ashton Kutcher and Twitter CEO Evan Williams in attendance, but Gowalla had the bigger-name performer: DJ and electronic artist Diplo, who drew the crowds into the Belmont's outdoor courtyard despite the rain.

Gowalla also had a big charity partner at its party: the Lance Armstrong-founded Livestrong. Using Gowalla to "check in" to the party earned users a virtual Livestrong bracelet and donated $1 to the cancer research foundation.

But Foursquare's real-life social activity at SXSWi didn't end with its party: All week, employees had used sidewalk chalk to set up matches of the popular playground game foursquare outside the Austin Convention Center. (That's co-founder Dennis Crowley in the foreground.)