Peplum Jacket: YSL
Dress: Luca Luca
Medallion Belt: Burberry Prorsum (click here to see a close-up of it)
Eel Boots: Devi Kroell
According to the celebrity rags and fashion mags, it's no longer gauche for celebrities to wear items over and over again. (I think one rag even said, "Even celebrities are affected by the recession" or something to that effect.) But for us common people, we've always done it.
This dress is what someone once dubbed the "Caroline Kennedy dress." Yes, it's uber-conservative, and I mostly use it as an all-purpose dress: it's great as a pencil skirt underneath a jacket (surprisingly enough, I don't own a black pencil skirt!), as a funeral dress, or as a layering piece.
P.S. Brook & Lyn--I'm not sure why the pictures have that yellow tint, but I'll try to investigate.