This is definitely the most popular bag in late 2007. And this hit will spread to 2008! So far it has been in the arms of Ashley Olsen, Sienna Miller, Reese Witherspoon, Victoria Traina and Nicole Richie.
some nice replica I found online:

an authentic metallic one from Barneys

I will tell you how to spot the fake Givenchy nightingale bag very soon!!