Beijing

Twitter has been co-opted by celebrities and companies like Starbucks and Bank of America. Now, the San Francisco-based service, which allows people to post updates, or “tweets,” up to 140 characters in length, is being adopted to organize an global fund-raising event called Twestival.

Even in these grim economic times, institutions like the Whitney Museum of American Art are able to continue building their collections. Some are gifts from donors unaffected by the financial markets; others are acquisitions in the works before things grew ugly; and then there is art that seemed out of reach before but is now available because of changing fortunes.

People for the Ethical Treatment of Animals. PETA. Its approach to getting people’s attention is bold, ballsy, bewitching — and often includes ads that feature celebrities in their birthday suits.