If a friend needs to convert Flash videos files (.flv) to QuickTime, iSquint (Mac OSX) is very easy and has some advanced controls. A companion product VisualHub expands options further, but iSquint did a great job getting 'Gangsters' by The Specials to iPod format.
On Windows, there's the freeware apps Videora Converter. swf2avi and Riva FLV Encoder. I didn't try them, but there's a ton of pay products for Windows like ones by Wildform and On2.
At some point I wanted to find out what the fps rate of an FLV and can across FLV Knife, a handy Windows tool to view or cut flvs, and inject metadata. BTW, the Video LAN player VLC (Mac/Win) seems to play anything especially the Windows version.