I have been looking around for a while for a decent converter to allow students and teachers the ability to use content they are able to use on the net but in flash form for their movie projects with iMovie and Final Cut Pro. Also, if teachers have movies hosted on websites they rely on for course material, it is great to be able to capture that for them so they can play that content locally.
MPEG Streamclip is a great tool to do the convert. There are many out there, but most are garbage and/or cost money to find out that they are garbage. This one, on the other hand is very much worth a shot. Mac OS X or Windows applications.