So a while ago, I posted what I thought was a workaround for Megavideo's time limit. This was before I did thorough testing and didn't realize the version was out of date. I just finished downloading Cacaoweb a few hours ago and have watched three episodes of Sons of Anarchy in a row (a 45-50 minute show). I highly recommend using this if you watch a lot of Megavideo.
Link.
One thing it does require that I haven't yet come across in other add-ons is requiring you to download something additional. There were a few warnings on the link I provided hinting it was malware. I downloaded the required file and scanned it three different ways without a flag. Basically, the add-on intercepts the Megavideo page and overlays its own player over the normal Megavideo video and runs. I haven't noticed a significant decrease in quality or run speed.
Give it a shot, I'm enjoying it.