In a jogging stroller built for two
What does Britney Spears use to ferry son Sean Preston and the occasional half-sibling around in? According to Child magazine, she uses a triple-size Ice Blue Valco All-Terrain Stroller. This stroller, which has a swivel/lockable front wheel, lets you add a bassinet for your newborn, or a "jump seat" to accommodate a toddler up to 45 lbs., making it an instant double stroller without the hassle of buying another one.
Available at Baby-Outfitters.com for $499. It comes with a cup holder, matching footmuff and diaper bag, rain cover and tire pump.
Source: Child magazine, February 2006