Lady Gaga's crystal-studded, hoop-surrounded Grammy outfit made its debut in the window of Armani last night, when the "Red Carpet Retrospective" opened with a private party at the Armani 5th Avenue flagship. Even without Gaga inside it, that dress stopped foot traffic along 5th Avenue.

Opening in time for the Oscars, the retrospective is devoted to the Armani gowns worn on the red carpet by celebrities including Halle Berry, Penelope Cruz, Victoria Beckham, Beyonce, Alicia Keys, Avril Levigne and others. Lady Gaga's is the show-stopper, of course, but don't forget to check out the bead embroidery on Anne Hathaway's strapless blue dress.

We highly recommend everybody pay the store a visit, because these dresses are way more impressive in person than the photos which follow.

Here are some pictures frm Armani 5th Avenue