Replay A/V is a utility that will record streaming video, or for that matter any video playing on your computer.
Back in June I featured Freecorder, its sister product that records any audio playing on your PC.
What this means is that any audio or video that is playing on your PC (in Windows Media Player, Real Player, Quick Time, PowerDVD, WinAmp, iTunes, etc.) can be recorded using one of these two tools. This can be useful in grabbing a segment of a longer recording, or capturing streaming media into a file that you can save to your hard drive.
Note that tools like this provide the capability, but not the permission, to record any media that plays on your PC. You will need to be aware of copyright restrictions.