ooh I love short dresses! Before we decided on a DW we considered a hometown garden wedding... and if we had done that, I definitely would have chosen a short dress! When we decided on a beach wedding, I was more drawn to full-length gowns for that setting.
However, I do think a short dress would be amazing for a casual beach event. If you're into the 50's style tea-length, Candy Anthony makes amazing gowns, though pricey. Dolly Couture is a more affordable option, though the fabrics are synthetic. Priscilla of Boston also makes gorgeous short gowns.