[Blarg]

Laxatives.

Or you can stay up all night. I lost 30 pounds in ten days doing that once, got like 8 hours of sleep the whole time.

Seriously though, for stuff that won't endanger your life or make you very sick, I'll let other guys detail it, but would very much recommend that you drink NOTHING but water. Soda, juice, etc., has an unbelievable amount of calories in it and sugar, and that shocks your system into storing your calories as fat. Water helps you poop out more and faster, and is used for pretty much everything in your body. Drink at the very least the 8 glasses a day of water you commonly hear about, and more will be appropriate if you are exercising at all or just feel like drinking. Drink BEFORE you get thirsty.

And cut out all the salted and prepared foods you can.

If you can go without much in the way of starches, especially refined ones, you will loose weight very quickly and will be healthy doing it, too. Vegetables can provide your carbohydrates fine while giving you next to no calories. They are a dieter's dream because they are very nutritious and you can gorge yourself silly on the non-starchy ones without putting any weight on at all. Seriously, you don't have to ever be hungry if you make the majority of your diet non-starchy veggies and lean meats and fruit.