The same pretty much applies. That script, which I had copied from the source I provided, was a specific for the YouTube videos that are also available in QT format (it puts another link on the page and that goes to the QT movie).
Other sites will have their own methods and policies and if Flash is the format, then that is not so easy to download on a Mac. That said, a quick Google search (using +download flash video on a Mac+) brings up a number of utilities that might fit the bill, such as
http://www.freemacware.com/flash-video-downloader.