Just thought I'd post a link to another free 3D movie player called Stereoscopic Player at:
http://www.3dtv.at/Downloads/Index_en.aspx
I think it is freeware. It hasn't said anything about registration or payment.

It supports many different movie types and has tons of options. It played dual stream automatically but the side by side I had to tell it how to play (side by side, aspect ratio, left side first). It looks really good and will let you play in a widow or full screen. This player and Bino (another free player) should be in everyone's toolbox.

Cheers!

Well Stereoscopic Player is a commercial product, it costs 39 Euros ( http://www.3dtv.at/Shop/Index_en.aspx ), but its well worth it. I bought a license years ago and have been able to upgrade for free and use on every machine I've built. Very good deal. Just wish Peter Wimmer (the author) could have found a better way to support 3D Blu-Ray. Otherwise it plays just about everything else.

Thanks! I see the Buy option under help now. I wonder what the limitations are for the free version? I guess I'll find out. His web pages don't say much about it being a pay product. I guess I'm back to Bino if this one craps out.

I remember it used to have a timed limit, maybe 5 or 10 minutes at a time (then you'd have to restart the program). Not sure if they changed that or what, but its certainly not freeware.

Ha! It's about 5 minutes of play then it gives a message and stops. If it were more reasonably priced, at about 10 dollars, I probably would buy it. But 39 Euros is too much Thats OK. I already bought Cyberlink PowerDVD 11 and it seems to play MKV files as well as blu-ray 3D. I'll just use it and the free Bino. I can't afford to buy all the players.

just use sview
http://sview.ru/en/download

sView is great, it's emulated opengl page-flipping mode is a lot more robust than Stereoscopic players.

Other options:
Bino is an open source option, that suppors side-by-side, top-down and can translate it to anaglyph and other formats. It also allows you to tweak the horizontal and vertical offset of the images.
The KMPlayer also supports 3D nowadays. And it's a pretty good video player overall. But alas, it's a bit spam-adware-y and tries to install toolbars, so be wary.