George Clooney Keeps a Stiff Upper Lip with a ‘Stache

George Clooney was snapped leaving West Hollywood, California, restaurant Dan Tana’s last night.

In recent months, the L.A. eatery has been frequented by stars such as Hilary Duff and her hockey-playing beau Mike Comrie, Cameron Diaz and Liv Tyler.

But what’s up with George’s moustache?

The actor is currently shooting the film Men Who Stare at Goats (due in theaters in 2010) where he stars alongside Ewan McGregor and Jeff Bridges as a reporter in Iraq.

The 47-year-old is also heavily rumored to be reprising his role as Dr. Doug Ross in ER’s series finale next year. He was last seen on the medical drama in 1998.

Could Clooney’s ‘stache be the look he’s sporting for either of those projects?