YouTube Overlays, Foursquare Plays, American Apparel Displays

- Foursquare was all the rage at SXSW this year. And they had a killer party with Ashton Kutcher in attendance. Now a new, location-based app, CauseWorld, allows you to check in to a box of Tampax. And other products. For charity. So it's all OK.

- YouTube now offers something else to distract us from the video we are viewing: ad overlays.

- In partnership with LookBook, American Apparel has figured out how to pimp itself without resorting to near naked teens in underwear.

- More from Dos Equis' The Most Interesting Man.

- Revision3's Jim Louderback crashes SXSW. Complains about it. Gets slapped in the face for it.

- Vodafone's Madame TreSesti is offering people free "social readings" based on LinkedIn, Twitter and Facebook streams.

- Be sure to grab a copy of Engage, Brian Solis' new book Engage which promises to help "champions, decision makers, and executives understand the impact and potential of new media and how, when, where to integrate it into mix."

- Be sure to check out the latest from The Barbarian Group: a new site for the Rock and Roll Hall of Fame.

- Like coffee? Like calendars? British photographer Miles Aldridge has been given the task of visually interpreting six of the ultimate Italian music classics: Va' Pensiero, Guarda Che Luna, 'O Sole Mio, Con Te Partirò, Baciami Piccina and Nessun Dorma for Lavazza's 18th calendar.

- It Doesn't Matter.