Crimped hairstyles are not very popular today (were they ever?), but doing something different is a popular way to dress up your hair for an important formal event, including prom.

Scarlett Johansson wore crimped short hair at a Hollywood event just once. This particular crimped style has wider crimping than average, and the effect of that is to create more volume and give her hair a retro look. The waves don't make it look like a traditional retro wavy hairstyle, but it looks a little like some flapper girl hairstyles of the 1930s.

Scarlett wore a nice formal vintage silver necklace with her slightly retro hair. She had bright red lipstick on her full lips and classic red nail polish on her very short red nails.

The popular celeb wore a conservative sleeveless black evening gown. The straight neckline is perfect—it's sexy but not extremely provocative. Unlike some of her later formal dresses, such as that infamous yellow satin dress, this one leaves something to the imagination.