Travel Technology - location of cache files - Vista?

There is a file I viewed earlier today, a video file that I was played with the macro media flash plug-in. Unfortunately I can't figure out where this file is stored on my laptop (vista) as I would like to capture it from my cache and save a copy.

Where does Vista store these files? I am using Firefox and viewed the video after accessing the website, with a flash pop-up.

Can anyone help me?

Merci,
MapleLeaf