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With over 26,000 followers, West Hollywood’s Roxy Theatre is the most popular club on Twitter . Just short of half a decade earlier, however, the fortunes of the historic venue and many of its neighbors on LA’s infamous Sunset Strip were waning and in need of serious attitude adjustment. We had a chance to talk with Nic Adler, owner of The Roxy and the man behind the club’s transformation from “castle on the hill” to social media juggernaut, about how Twitter and other tools helped not only reverse the fortunes of businesses on the Strip, but build up a stronger, more vibrant local community

Continuing with a very source agnostic digital book strategy, Barnes & Noble has announced it will soon be offering an e-reader app for the Apple iPad .

Live TV can be tough, especially if you’re in a cranky mood. Case in point: WVLT TV Volunteer News reporter Gordon Boyd, whose on-air freak-out has gone viral this week.

Last week, an App Store error got the latest version of Foursquare for the iPhone into a few users hands a little bit early. That hiccup resulted in the app briefly disappearing from the App Store before finally returning early yesterday . Now the newly designed version of the app is in the App Store and available for everyone to check out.

This post is part of Mashable’s Spark of Genius series, which highlights a unique feature of startups. If you would like to have your startup considered for inclusion, please see the details here . The series is made possible by Microsoft BizSpark.