The singer has fun at a Nickelodeon show. Plus: J.Lo & Marc, Jake Gyllenhaal and more

IF THE SHOE FITS...

It's still summer, but Kristen Bell – who's starring in the horror film Pulse, out Friday – gets a foothold on fall's new looks during a shopping excursion Monday at the Elie Tahari boutique in New York City's SoHo neighborhood.