Any ideas how to open a '.flv' file?
Install Perian. It works in QuickTime Player X on 10.8.
You also may be able to open it in a web browser, using the "open file" command of the browser, presuming you have Flash Player installed on your system.
Go out to videolan dot org and download latest VLC player. It handles .flv input and many others.
VideoLAN - Download official VLC media player for Mac OS X
Retrieving data ...