I have had some luck pasting the URL into an updated version of RealPlayer and then using the download option. Sometimes all I get is a pair of files that seem to be index markers for where the source is on the internet. One of those files acts like a shortcut and directs RealPlayer to the correct web page and plays it and THEN I can use the download option.
If successful, the downloaded file is an .flv file and will be at:
c:\Documents and Settings\Username\My Documents\My Videos\RealPlayer Downloads
The path might vary depending on the particular sub-species of your Windows OS.
The downloaded files seem to run about 150MB per half-hour, give or take. That would put a regular movie at about 600MB.
HOWEVER -
I have noticed that some content seems to be masked or hidden by advertisements. If a video is preceded by an ad, all I get is the ad and not the following video.
There's a product called Replay AV that might have a new version that will handle this issue, but I haven't seen it in action.