I did a bit with it a while back and found it to be useful.
The somatics approach uses gentle movements to return awareness to those parts of the body that have forgotten to be flexible and alive. I believe that the person who put this together trained for a while with Moshe Feldenkrais.
The book – see link below – has a good explanation of the movements as well as pictures that I found easy to follow.
As far as I understand, ‘somatics’ was invented by Thomas Hanna, who is the author of that book – (although he may have just come up with the term). I’ve seen and followed one of his videos which was very effective. As dwd said the movements are designed to bring awareness into muscles that have been unconciously tense over a period of time.
The somatics technique is especially good for people with very bad posture, the elderly or unfit, since it’s generaly very gentle.
Some of the principles are very similar to what’s known as ‘resistance stretching’ – which have been popularised by Pavel Tsatsouline and Bob Cooley.
If you’re pretty fit, flexible and body-cocious, you may find the results from somatics excersises not so dramatic (although you may be surprised once in a while). I’ve recently bought Bob Cooley’s book and have been doing the stretches – I’ve found it very effective.