The perfect formula for rocketing toys up the list of best sellers: Take a parent who once owned them, add children to whom they can pass on their nostalgia and mix in a hit movie to make it all seem cool again. It's worked to renew interest in any and all things Muppet-related. Certainly, the kinder, gentler Muppet monsters of Sesame Street -- especially Elmo -- have been huge gift items every year (recall if you will the mob violence inspired by the search for Tickle Me Elmo dolls). The more adult-friendly Muppets -- Kermit, Miss Piggy, Fozzie -- have seen their reign of toy shelves ebb and flow over the years. Now, with a hit movie in theaters once again, a whole new line of Muppet memorabilia is once again on store shelves, and older items are finding new life (and higher bids) on eBay.