Mac Free 3D Video Converter allows you to convert regular 2D videos to anaglyph 3D format. You can convert family videos and watch your special moments in the way you had experienced them. The application can create an anaglyph video automatically from the file of any popular formats, like MP4, DVD, AVI, WMV, MPG, OGG, MKV, MOV. Also, you can choose any format of the resulting video file and profile for almost any media players (Zune, iPod / iPhone / iPad, iRiver, PSP, Archos, xBox).
Easy to use and lets you creating different types of 3D, from anaglyph (red/cyan, etc.) to side-by-side and top/bottom forms of 3D for you TV. It also gives you many option to do exactly what you want to.
Cons
None that I can think of so far, but I've only used it once.