[Les Allen]

In my experience, when you are in a lucid dream or projection, you spin the dream body just like you do when your a child trying to get dizzy.
I did an experiment in conjunction with other lucid dreamers, in a lucid dreaming forum that was on a lucid dreaming website.

The experiment was to spin when a lucid dream was fading and the dreamer was waking up. The sensation of spinning seems to serve to give one enough sensations to trick one into staying in the dream, perhaps due to the fact that you can really really feel the spinning sensation. The results were varied, sometimes the dream scene would change, sometimes a false awakening would ensue, other times one would wake up.

The highest percentage of results, though, was that the dream would re-solidify. I don't recall the actual results in terms of how many dreamers conducted the controlled experiment, or what the actual percentages were, but they concluded that it was one of the most effective ways they had to maintain the dream scene.

Unfortunately they discontinued the forum. Not sure why.
Dr. Stephen Laberge was the founder I believe. He has a book out called Exploring the World of Lucid Dreaming.
Good book, lots of techniques.
It is geared more towards a scientific approach to dreaming aware.
A must read, in my opinion.