How to spot-clean a dry-clean-only prom dress?

I've got this awesome blue dress I'm going to wear to a dance on Friday but it's got some little spots on the skirt. It is a simple (but elegant) polyester dress. Taking it to a dry cleaners will be more complicated than I thought, so I was wondering if there was a way to just take the small spots out by myself. Is there a way to clean it without making it look worse?