Ok probably most of you know this trick but for all those who don't here it is.
As you know to download video from mv you must have premium account. Is it possible to do it without paying ? Yes. And it's very simple and very very fast O_O
For this you will need simple IE explorer.
1. Open your MegaVideo video in your browser and let it load fully
2. After you are done watching the video online, go to Tools -> Internet Options -> Settings -> View Files (For IE)
3. Now you will get a large size file with long name and unknown type there
4. Copy and paste that file at desktop, this file is the video file in flv format
5. Rename it with flv extension, say e.g. IjustDLyou.flv
So while you watch it you actually download it at the same time
Cheers,
MSJ.