This is from the Amazon wiki on “stereoscopy”:

• 10 mm Panasonic 3 D Lumix H-FT012 lens (for the GH2, GF2, GF3, GF5 cams and also for the hybrid W8 cam).
• 12 mm Praktica and Medion 3D (two clones of the DXG-5D8 cam).
• 20 mm Sony Bloggie 3D.
• 23 mm Loreo 3D Macro lens.
• 25 mm LG Optimus 3D and LG Optimus 3D MAX smartphones and the close-up macro adapter for the W1 and W3 Fujifilm cams.
• 28 mm Sharp Aquos SH80F smartphone and the Toshiba Camileo z100 camcorder.
• 30 mm Panasonic 3D1 camera.
• 32 mm HTC EVO 3D smartphone.
• 35 mm JVC TD1, DXG-5G2V and Vivitar 790 HD (only for anagliph stills and video) camcorders.
• 40 mm Aiptek I2, Aiptek IS2, Aiptek IH3 and Viewsonic 3D cams.
• 50 mm Loreo for full frame cams, and the 3D FUN cam of 3dInlife.
• 55 mm SVP dc-3D-80 cam (parallel & anagliph, stills & video).
• 60 mm Vivitar 3D cam (only for anagliph pictures.
• 75 mm Fujifilm W3 cam.
• 77 mm Fujifilm W1 cam.
• 88 mm Loreo 3D lens for digital cams.
• 140mm Cyclopital3D base extender for the JVC TD1 and Sony TD10.
• 200mm Cyclopital3D base extender for the Panasonic AG-3DA1.
• 225mm Cyclopital3D base extender for the Fujifilm W1 and W3 cams.

via Stereoscopy – Shopping-enabled Wikipedia Page on Amazon.

For those new to 3D, the interaxial distance is the spacing between the center of the left camera lens and the right camera lens. The interaxial is a critical component to creating good 3D depth effects. Too large, and the viewers eyes will hurt. Too small, the depth effect will be minimal. The key is to select the right lens spacing for the “depth box” in front of the camera. Objects within the depth box will have appropriate parallax and good depth effects.

Most consumer and semi-pro 3D cameras have relatively narrow lens spacing – they are perhaps best for shooting 3D photos or video of kids in the backyard or at the park. Beyond a few tens of feet (or meters) the depth effect vanishes and those parts of the image appear flat.