I agree with most of the comments above. One site, with some high bandwidth content selectable through links. Let them know what's available to them.
A lot of people do this because they want a pretty flash site. Unfortunately, most flash sites don't work well for
SEO and search engines. I'd love to see people start fusing overall quality design, for the end user, and built for their target audience.
Build a clean, standards compliant site, with options to your high bandwidth content.