The giant fashion bash known as the Costume Institute Ball is tonight. We'll leave its reporting to Vogue - it's their party, after all - but we will examine one curious tidbit today: Why is Lindsay Lohan going as the guest of Bally? In the past, Lindsay's been taken to parties by Karl Lagerfeld, Francisco Costa of Calvin Klein, and Marc Jacobs. Why is she switching her couture chaperone to a brand that's more prized by the soccer mom set? Possibilities: 1. Lindsay may have lost her fashion fizz. After misbehaving at last year's CFDA Vogue Fashion Fund awards, other designers are worried that Ms. Lohan may irk the Voguettes and compromise their favor with the magazine. 2. Bally may be paying Lindsay a lot of money. The exposure is undoubtedly great for the line, their new creative director Brian Atwood can actually make cool clothes for cooler girls, and this wouldn't be the first time money changed hands before the Ball. 3. Lindsay might like the Bally dress the best. After all, when you've worn every major designer before you're 21, you're bound to be over a label for label's sake. Any options we've missed?