Give me a moment to put up my Geek Flag.
There we go. Now. It wouldn't be too hard to focus a couple laser beams (eight would do it), at a single point about one meter above the emitter. They would have to be hellaciously powerful though, to do the things a lightsaber can do. There is at least one time where a character jams one into a series of armored doors, and the way the heat transfers implies that the beam maintains coherency through all that plating.
The problem is the power output. We have the technology to put out a single beam with that kind of power, but it's housed in a very large building, and it takes a while to charge up.
Bottom line is that I think light sabers are as cool as everybody else does, but I also think that simple physics makes them impossible.
I'm just gonna fold my Geek Flag up and leave, now. Thanks for listening.