LightTable application provides an environment for you to practice the multi-touch gestures Mac OS X 10.6 or later offers (if you also have a multi-touch capable trackpad, which most Apple laptops have). I tested this program on a Macbook Pro running OS X 10.6.
The basis of this program is to drop images down onto the "light table". The first thing I noticed was that the Open function the program has simply doesn't work - apparently, you're supposed to drag and drop images from Finder into Light Table. This is understandable to me, but having an Open function that doesn't work seems pointless. Once you have images on the table, you can click on them and change the size using multi-touch gestures, which are quite intuitive. Double-clicking on the image takes it out of the frame and you can change the size out of the frame; double-clicking again will put it in the frame again, but this time cropped. Three fingers swiped horizontally brings a side-bar to change the frame thickness and corner radius.
As only a program for demonstration for these gestures, I think it works fine - but I am still confused as to exactly what it is. If it is purely to use multi-touch gestures, it lacks in demonstrating some of the gestures that 10.6 and up have - such as the rotate function which seems to me like an obvious one to include in this program. The program doesn't seem that useful to me personally, although having used a multi-touch trackpad for quite some time, it's possible this program is helpful for someone new to these features. One thing I was disappointed about was the lack of Help - there is a Help tab, but if you click on "Light Table Help" it says that help is not available for Light Table. Maybe, that will appear in a later version.
I think that this program could have good potential if it was expanded to include more features and a written guide for what exactly it does and what exactly its purpose is. I feel as though I'm missing some key element here, but maybe all it does is lets you play around with your multi-touch trackpad. In that case, it's mildly entertaining and helpful.