I had a Razor3D system, which used LCD shutter glasses, the same as the original Imax system (not sure if it's evolved since then).
Basically, there was a small control box about the size of a packet of cigarettes, to which you took the video out of a DVD player, and then connected the box to the video in of a television.
Viewing 'field-sequential' DVDs was amazing, with genuine 'in the room' effects. Unfortunately, there were only a tiny number of 3D DVDs available for it. Even more unfortunately, the system only works with CRTs (something to do with the way the screen is refreshed), so I sold it on eBay.
The glasses were quite comfortable (I don't wear glasses normally, though I do have some cheap reading glasses for ploughing through instruction manuals!), but I wouldn't to wear them too much. They worked by alternatively blacking out/clearing each lens, and got a bit fatiguing after a couple of hours.
I assume the new television 3D systems are different to this?
There's also the old 'one eye' technique, demonstrated by the BBC about 20 years ago. This uses cheap cardboard glasses with one slightly opaque lens, and a clear opening for the other eye. It works by delaying the image to one eye, and the effect can be seen on any television program - but only if something is moving in a specific direction (right to left, or possibly the other way around), or the camera is panning in the opposite direction.
There are some DVDs* that include the glasses, and the 3D effect can be quite good, but depending on the program content it comes and goes all the time! And the effects are all into the screen, rather than beyond it.
I do think that unless they can perfect a system that doesn't require glasses, it will never enter the mainstream.
(* can't believe the price of this - I'll have to put my copy on there!)
PS3 / 360 / Pioneer BDP-51FD / Sony L40-W4500 / Panansonic DMR-E95H / Onkyo 706 / Kef Reference One fronts / Kef Ref 100 centre / Kef HTS2001.3 surround back x 2 / Polk LS f/x bipole rears x2 / Velodyne VA-1215X sub / Stands Unique rack / Argos TV stand