YouTube videos are stored in the Flash Video FLV formats. However, FLV formats are not as versatile as other existing formats such as AVI, WMV or MOV.

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kuanhoong dot com » Convert YouTube video from FLV formats to AVI …

Chris Anna, a student from the Digital Storytelling course, just posted about YouTube Doubler, which bills itself as a mashup helper. And it is immediately apparent to me how this could be a useful tool for seeing how two clips match up …

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YouTube Doubler at bavatuesdays