Celebs at the Montblanc John Lennon pen launch

Singing sensation Christina Aguilera was all glamour in this belted black strapless dress with peep-toe heels at the launch of the Montblanc “John Lennon Edition” pen at Jazz in the Time Warner building in New York City. Christina Aguilera rubbed elbows with an eclectic group including Gabrielle Union, Olivia Palermo, Helena Christensen, Susan Sarandon and Christian Siriano.

The Hills star Kristin Cavallari opted for an elegant shimmery dress for the event.