XDM can capture FLV videos from any site like(Youtube, Metacafe, Google Video etc) using Advaned Browser Integration.
To capture videos goto the webpage which contains the video and play the video. XDM will capture the download link autometically. To view the link Goto XDM Menu->File->Grabber



Note: XDM will capture Videos only if XDM is in sync with the browser (Browser name is shown in XDM status bar)