Try "CosmoPod". It's a plug-in for Safari. You add its button to your tool bar and it's enabled when there is flash movie content on the current page. Click the button, and it's downloaded. You can use it with the perian FLV decoder, and it will automatically convert it and, if you like, add to iTunes. Or, you can leave just download the FLV and convert it using something like VisualHub. (I'm using it that way, as I'd rather not mess with the codecs, unless I have to)