Check out another of my videos: “BREAKDOWN: Select and Mask vs. Refine Edge – Photoshop CC”
Check this video out at Hi-Res here: http://www.tutvid.com/tutorials/dreamweaver/tutorials/transparentSWF.php
Take that SWF file with lots of open space(be it an animation walking around or maybe that slick semi opaque video, or maybe the more practical drop down menu) and place it on a div that floats above your site and allows you to see whatever is underneath of it! Watch this one! You will learn a thing or two. please check out http://www.tutvid.com more more great stuff!