Lots of ways to do this. The one I'm most familiar with is changing from an "8 hours in a row" pattern to one with more rests during the day, but for much shorter periods. As always you can find a good overview at
Wikipedia. I've tried the Uberman sleep cycle a couple times. Right now I'm taking 2 or 3 naps per day, with one longer sleep at night for a few hours at most. For years I got a regular one nap per day. Perhaps if there is enough interest I'll setup a special forum just for folks interested in this.[/b]