A giant billboard has been erected in New York's Times Square to celebrate veteran comedienne Betty White's 92nd birthday on Friday (17Jan14). The ad, from executives at Sharper Image retailers, features a photo of the Golden Girls icon, alongside the message, "Still sharp after 92 years! Happy Birthday, Betty White." Company bosses have promised to make a donation to one of the actress' favourite charities, the Los Angeles Zoo, if fans snap photos of the image and post them on Twitter.com. However, the ad will only stay up for 24 hours.