Compressor cant do it. You can download Perian (perian.org) and get that free plugin, a restart of your computer should mean that when you reload final cut after restart, you will see FLV in the drop down menu in Quicktime Conversion. If that does not work Visual Hub is cool, out put a file from Final Cut (if your going to flash an H264 file usually does me, amend the kbps to fit