What should i wear to a 1999 themed rave? help?

eeeep! i need help. i don't need EXACT outfits but some ideas?! usually i'm pretty creative on my own but 1999 is stumping me! this was when the y2k scare was going around, sooo something? iunno! haha i'm failing hard at brainstorming what to wear. please help!! ^___^ i'm a girl, by the way! thanks all!