I can't speak highly enough of the Silva method. I first started using it in the mid-70s, just learning from books. Later, I bought the Ultra course from Nightingale Conant (the one with Dr. LaTourrette). I find the Silva techniques to be some of the most effective I've used--ever, bar none.
If you buy the course (or check out some of the inexpensive books at amazon or eBay), you might find some of the techniques are just a little familiar.
There is a good reason for this. According to my understanding from what I've read, Jose Silva studied the mind and body in depth for many years before even thinking about teaching others. In a sense, he learned from a lot of people, either in person or from their books--some of them quite ancient.
As a result, you might notice traces of this, touches of that in the courses. He weeded out what didn't work for him, and included what did. The result is what is being marketed now. I have no doubt he would have improved it still more, but he has crossed over to the other side.
I find the techniques to be immensely practical. You can use them anywhere, almost any time. (Do I ever have trouble finding a parking spot? Not since the mid 70s!) They blend well with other things, from yoga to QiGong to Reiki and so on, simply because so many elements of so many other techniques are part of the Silva methods.
As with many of these kinds of courses, you can "preview" the Silva method(s) by reading some of the books first (they are quite generous in sharing techniques in their books, unlike some organizations).
One of the best was written in the 70s by Jess Stearn--I'm told the method he writes about is actually an offshoot of what was being taught back then, yet "The Power of Alpha Thinking" is a very concise and helpful manual--written so well it reads a lot like a novel. I sometimes find this book in the used book stores, or on amazon.com.
Another is the recent offering, "Silva Ultra-Mind" by several authors including Dr. LaTourrette--a paperback that is often found in libraries and for sale used in the usual places.
So check it out, test drive it a bit, and see if you want to get the course on CD.