In a program like Flash, use symbols. Audio can often contribute to half the bloating in multimedia productions. Fortunately, programs like Flash 5 and Director 8 import MP3 audio. Ask yourself, is it critical to use stereo when mono will do the job. Stereo doubles audio file size.
Some multimedia programs generate reports detailing bandwidth use for an application.
They will point out potential download choke points that might have to be addressed. The key is to find that happy compromise between file size and quality. I find that audio is often the most vital part of a multimedia production. Unfortunately, it's usually the part designers invest the least amount of time and effort. Combining voiceovers, sound effects and music require as much planning and hard work as the other half of the production.