So that whole mobile local, “check in when you go out” space? It’s so on.

This week we pit three of the top local check-in services against each other for the title of Check-in Champion: Foursquare, Gowalla, and Yelp.

As you may know, we’ve been doing a long-running Faceoff Series here at Mashable where we pit similar services and products against each other to see who can win the hearts and minds of Mashable readers. This time we look at two fairly established competitors in the mobile local space, Foursquare and Gowalla, and see how they stack up against the major competitor who just stepped in to challenge them: Yelp.

The long-standing local social network just last week added the ability to check-in to venues you visit, putting it squarely on the playing field in the mobile local arena. Yelp doesn’t yet offer the same level of “game-like” points and achievements for contributing your social life’s location metadata, but it does offer an incredibly deep set of data surrounding place information and user ratings and opinions. It will be interesting to see how this space shakes out with these various players’ different takes on the mobile social experience.

And right now, we’re asking you, dear Mashable reader, to stake your claim on which of these three mobile applications is your favorite. If you could only check in to a single site (and let’s face it, who wants to keep up with a multitude of check-ins every time you arrive somewhere?), which would you pick?

Leave your vote below; the poll will remain open until noon PST on Friday, January 22. Be sure to let us know in the comments who you voted the way you did, too.

Who would win in a fight: Yelp, Foursquare, or Gowalla?(online surveys)

Web Faceoff: Overall Results

Week 1:
– Mozilla Firefox vs. Google Chrome
– WINNER: Firefox, 4600 votes (Chrome: 3310 votes, Tie: 911 votes)

Week 2:
– Tumblr vs. Posterous
– WINNER: Tumblr, 1809 votes (Posterous: 1496 votes, Tie: 256 votes)

Week 3:
– Pandora vs. Last.fm
– WINNER: Last.fm, 1187 votes (Pandora: 1156 votes, Tie: 122 votes)

Week 4:
– Twitter vs. Facebook
– WINNER: Facebook, 2484 votes (Twitter: 2061 votes, Tie: 588 votes)

Week 5:
– WordPress vs. Typepad
– WINNER: WordPress, 2714 votes (Typepad: 267 votes, Tie: 357 votes)

Week 6:
– Windows 7 vs. Snow Leopard
– WINNER: Windows 7, 3632 votes (Snow Leopard: 3278 votes, Tie: 121 votes)

Week 7:
– TweetDeck vs. Seesmic Desktop
– WINNER: TweetDeck, 3294 votes (Seesmic Desktop: 1055 votes, Tie: 260 votes)

Week 8:
– Microsoft Office vs. Google Docs
– WINNER: Microsoft Office, 1365 votes (Google Docs: 994 votes, Tie: 315 votes)

Week 9:
– Apple iPhone vs. Google Android
– WINNER: Google Android, 3323 votes (Apple iPhone: 1494 votes, Tie: 228 votes)

Week 10:
– AT&T vs. Verizon
– WINNER: Verizon, 1161 votes (AT&T: 538 votes, Tie: 118 votes)

Week 11:
– Google vs. Bing
– WINNER: Google, 2180 votes (Bing: 519 votes, Tie: 97 votes)

Week 12:
– iPod Touch/iPhone vs. Nintendo DS vs. Sony PSP
– WINNER: iPod Touch/iPhone, 704 votes (Sony PSP: 639 votes, Nintendo DS: 482 votes, Tie: 108 votes)

Week 13:
– Digg vs. Reddit vs. StumbleUpon
– WINNER: Digg, 14,762 votes (Reddit: 11,466 votes, StumbleUpon: 2507 votes, Tie: 1032 votes)

Week 14:
– Old versus new Twitter retweets
– WINNER: Old style retweets, 1625 votes (New style retweets: 699 votes, Tie: 227 votes)

Week 15:
– Gmail vs. Outlook
– WINNER: Gmail, 3684 votes (Outlook: 980 votes, Tie: 590 votes)

Week 16:
– Boxee vs. Hulu
– WINNER: Hulu, 626 votes (Boxee: 591 votes, Tie: 106 votes)

Week 17:
– Nexus One vs. iPhone 3GS
– WINNER: Nexus One, 6743 votes (iPhone 3GS: 2818 votes, Tie: 592 votes)

Tags: -local, foursquare, gowalla, iphone, lbs, Mobile 2.0, mobile local, polls, social media, web faceoff, yelp