Best Product for Teeth Whitening....?

I have a very important party to go to on Saturday. My teeth are yellow-ish. What's a product that will make my teeth white by Saturday? I'm going to Walmart later today to purchase a kit, and I want real opinions, not what the manufacturers say about their own product. Oh, and possibly items less then $25? I know that's kind of impossible though. Thanks In Advance :)
--------------------
I've heard that using Baking Soda does wonders for whitening teeth. I did a little quick search and read that it can make your teeth whiter in just 14 days! (No, I'm not advertising lol) Wet your toothbrush with some water and dip it into baking soda. All of the bristles should be covered so that your toothbrush is white. Brush your teeth for 2 minutes (spitting if necessary) two times a day. Spit out the baking soda and rinse your mouth clean with water. If there is a tingling or burning feeling in your mouth, this is bad. See "Warnings" for what might not be normal. Brushing your teeth twice a day can be monumental for the whitening of teeth even without these tips & tricks - especially with the regular use of dental floss and mouthwash. Tips: After brushing your teeth, brush your tongue with your favorite spice and/or use a fruit. Bad breath is related to teeth only when they house food debris and plaque. The main cause of bad breath is bacteria growing on the gums. An alternative method involves putting baking soda on the toothbrush and wetting it with a little bit of hydrogen peroxide (the cheap stuff one pours on cuts). It really does work! Warnings: Do not use this method too often as the abrasive can permanently damage the enamel of your teeth. There are some special toothpaste brands (often for smokers) which contain much gentler abrasives than baking soda. They can be used daily without any risk for the health of your teeth and help to remove not only tobacco stains but also stains from coffee, tea, and wine. Baking soda can dissolve orthodontic glue. Do not use this method if you have braces or a permanent retainer. Best used only once or twice a month. Don't brush too hard for a longterm as it may damage your enamel (which is called as abrasion),leading to hypersensitivity. Don`t put too much baking soda or it will cause teeth to bleach. Now, there are quite a few warnings, whether or not you want to do this is totally up to you, I'm just here to help :)
Source