Replying to Hollywood costume ideas

so prom is this weekend, and i guess it is themed as hollywood, which i think is personally really shitty. i was much more down to dress up as arial from the little mermaid, which was the previous theme. anyways i guess this is the night to dress as my favorite hollywood starlet. i need some ideas. i thought i might be keith ledger and pretend to be really coked out and maybe aided by alka seltzer, and maybe my date could shave her head and bring a shot gun and pretend to be Brittany Spears.