On Black Friday I bought some of these new HairDo clip-in bangs ($22) that Jessica Simpson and Ken Paves make, and I'm officially a convert. They're synthetic (so no worries about where and who the hair came from), inexpensive, easy to use, and stayed in all day. It's the quickest, and maybe the cheapest, way to change up your look for the holiday party circuit. Just make sure you go into the store to get them. They have a lot of color options, but the bangs won't look good if they don't match your hair.
All Banged Up