If you're thinking about incorporating Macromedia Flash into your Web site, I suggest you read & perhaps order the report mentioned on this page:
"Flash's animation capabilities make it perfect for representing any information that has a time element. And it's zooming and panning capabilities make it ideal for representing spatial data. … You'll see what happens when designers get too clever. We'll show you why navigation panels are the wrong choice for Flash and the situations in which HTML beats Flash hands down."
I continue to believe that Flash is good to represent information that needs to be animated *because that's the best way to present the information*. I do not think Flash is good for navigation, and I think it is a huge usability error to create Flash splash pages. People skip those pages! In fact, Jared Spool of User Interface Engineering said that after watching thousands of people in their labs, they no longer call them "Flash splash pages"; instead, they call them "click throughs". Why? Because very, very, very few people watch them—instead, people look for the "Click to skip" link and get past the Flash as quickly as possible. The example I always use is Wal Mart—when you walk into Wal Mart, the greeter doesn't make you stop and watch a 45-second-long movie about how cool Wal Mart is. Nope. Wal Mart gets it—they want to get you in the door as quickly as possible! So why are you delaying the entrance of people into your Web site?
I guess my question is always, "How?" How will Flash help your web site? How will it better communicate your message? How can you justify it? How can you be sure that your audience will have the Flash plugin installed? How will Flash make your web site more usable?
More on this subject:
Problems with Flash
Inaccesible to disabled Web users: Flash images don't have support the ALT attribute, like IMG elements do. Even if Flash images did support the ALT attribute, they couldn't be read by a voice browser (which people with visual disabilities use), because anything inside the Flash environment can't be processed and read outloud by voice browsers.
If you're going to use Flash
You'll need some sort of way to detect whether or not your visitors have the Flash plugin installed. The best tool for this is the famous Flash detection script developed by http://www.moock.org.
In fact, http://www.moock.org has just about everything you'll need to create Flash animations.