Where, oh where, have the little dogs gone? The little dog dolls, that is. Bo, a Beanie Baby version of Barack Obama’s new presidential pooch, has been disappearing from shelves within hours of his arrival in stores. He has also become eBay’s latest pet project, with purchasers seeking double the doll’s $4.99 retail price online minutes after they buy it through retail outlets. Some are even asking more than $100.