You can try dressing up as an airplane, or a traffic controller. Other ideas would be to try dressing as a pilot or a flight attendant.
Costumeideazone.com is a great place to go for creative costume ideas. It gives you a variety of different themed costumes for all ages, both young and old!
Blues brothers is a good one, easy and recognisable, also straight :)
You can get some creative costume ideas at http://costumeideazone.com/. You can also get some ideas at http://www.indigo.org/halloween/page2.html
A couple of ideas are a Barbecue Themed wedding or a Citrus (lemon-lemonade) wedding. You can also have a Garden Themed wedding.
Costume ideas that begin with the letter i:Incredible HulkIndianIndiana JonesInmate
Jelly
Draco malfoy rumbleroar harry potter ron voldemort ginny chochang cedric digory (or however you spell it) quirl snape dumbledor thats about it i guess
you can have a fairy princess party
well its a bit obvious! Angel and devil are good or if not then look on the internet for costume ideas or look in costume shops
If you want costume ideas then the best place for that would be online on some Halloween websites. You can also just go to a website that has Audrey Hepburn costume ideas on their as well.
Lady Gaga
Family Fun Magazine offers some great Halloween costume ideas. They offer individual costume ideas or ideas you can use for the whole family! http://familyfun.go.com/crafts/ducks-662521/