The free way:
Inside Flash, Import > Import to stage and pick the flv file. Choose "Embed flv in SWF and play in timeline"
Right click and set document properties to the size of your video, move it around if needed so that it fits perfectly in the frame.
Then File > Export > Export movie and choose Quicktime (somehow AVI 24 bit buggy exports are buggy). Set the format to Animation, and store temp on disk.
That should be about it.
Vince Becquiot
Kaptis Studios
San Francisco - Bay Area