What can instantly transform your outerwear from uptown chic to downtown cool? The answer is simple: it's in all in the leather sleeves! That's right, we've spotted leather sleeves adorning everything from sweaters to boyfriend coats, giving these classic wardrobe staples a tough-girl twist. Since we're totally smitten with this of-the-moment look, we've rounded up a few of our favorite celebrity examples--along with some must-buy products too--for today's slideshow. Hope you enjoy!