Birthday Ideas for a 23 year old?

Why don't you have a color-themed party. Like a Black and White party, where everyone dresses up in the clic 1920's style clothing that is all colored black and white. You can even suggest that girls dress as flappers or something like that. You can also cut out like an old 1920's style car and hang it on the wall. You could create a "bar" and serve mixed drinks. Also you could play swing dancing music and have a silent movie playing on a screen or something like that.