The bride's dress is often the focal point for any wedding, in both the ceremony and the budget. But this second point doesn't have to be the case-there are many options now that will save you a lot of green on your white weddings.
First, if you happen to be or know any kind of seamstress, see about having them design and sew the dress for you (or designing or sewing your own). This is a huge favor to ask someone, but chances are it will save you oodles of money, as you're paying for nothing more than materials and labor. You can get a bridal catalog look without the bridal catalog price, plus the dress will be custom made to fit you, so no tailoring needed.
If hand made isn't an option, it's still possible to get a dress from a major retailer on the cheap. In many of these stores, the employees work on commission and will be more than willing to come to an agreement about the price to get you to buy. Regardless, don't make unreasonable demands and treat your clerk with courtesy and respect. Other ways of saving at the big end retailers include taking advantage of sample sales, being lenient about the size (the dress doesn't have to fit like a glove), switching to lower-cost material, or using a white bridesmaid dress. This last option is a great little trick that will easily save you hundreds of dollars, especially if your taste in wedding dresses runs more on the simple, understated side.
You can also opt to buy a used wedding dress (eBay is great for this). There are also companies that rent designer gowns, for weddings and otherwise, out for a day or evening at the fraction of the cost of actually purchasing one. They generally have a great selection in styles and sizes, as they pull their products from all over: factory showrooms, fashion shows, women selling their old gowns. If you're the sentimental type who would want to hold on to your wedding dress for posterity, this may not be an option for you, but do remember that it's cheaper to rent the dress and keep a picture of it than to buy the dress outright.