What’s Hot in Social Media This Week

via Lauren Indvik @Mashable

Welcome to this week’s edition of “What’s Hot in Social Media,” a series in which we revisit the week’s most popular stories concerning social networks.

We’re keeping our eye on three interesting developments this Thursday.

Gowalla Integrates with Foursquare & Facebook Places

If you can’t beat ‘em, join ‘em — location-based social network Gowalla has released version 3.0 of its iPhone app, which now integrates with two of its bigger and better-known rivals, Foursquare and Facebook Places. Using Gowalla, users can now broadcast their checkins on both networks, as well as Twitter and Tumblr, and even secure Foursquare badges and Facebook Deals. Users also now have access to a Universal Activity Feed, which aggregates checkins from Foursquare, Gowalla and Facebook in real-time, so they can keep track of their friends no matter which location-based app they use.

Non-Profits Raise Awareness via Social Media for World AIDS Day

A number of non-profits turned to social media to raise awareness for World AIDS Day on December 1. Social media-active celebrities, including Lady Gaga, Justin Timberlake and Ryan Seacrest, went silent on Twitter and Facebook as part of a $1 million fundraise. (RED) used Facebook, Twitter, Foursquare, Flickr, Eventful, Meetup and YouTube to create a map to highlight World AIDS Day activity across the globe. And the United Nations AIDS Program (UNAIDS) worked to make its hashtag — #PreventionRevoltion trend worldwide on Twitter to raise awareness, among others.

Anti-Fur Protesters Take Over DKNY’s Facebook Page

The People for the Ethical Treatment of Animals (PETA) staged an anti-fur protest on clothing brand DKNY’s Facebook Page Monday. Thirteen different users changed their Facebook profiles photos to block letters and posted in quick succession on the DKNY’s Page to spell out the words “DK Bunny Butcher” in protest of the brand’s use of rabbit fur.