UPDATE: This plugin has not been updated in over 2 years. Please do not use this as it could cause major issues. Try the Web Dorado Slider Plugin as an alternate plugin. 5/24/2017)
Every so often I get contacted for WordPress theme customization and the client wants a Flash slideshow somewhere on the site usually the header. I have never incorporated that into a WordPress theme before mainly because I didn’t know how. There is a plugin that that is designed to place a Flash slideshow in a sidebar widget but it can also be used to place it anywhere on the theme. I will warn you that it can be a pain to get everything setup correctly to work on your WordPress header.
The Flashfader Plugin is needed to do this and as I said if you just want to use it in the sidebar there isn’t much to it. But if you want to incorporate Flash into your header then you will need to know a bit about the code on your WordPress theme as well as some graphic editing knowledge. The plugin was brought to my attention by a friend of mine who does graphic design and who I refer people to for custom WordPress and website headers.