I'm sure there are many variations to this problem. What worked for me was like McKenzie (sp?). Roughly, picture doing a pushup, except that every muscle in your body is completely relaxed, aside from your upper arms. You're sort of passively arching/tractioning your spine. Do it slowly and repeatedly. It should feel good. Do as many cycles in a day as you care for.

Beyond that, be careful when you get out of bed each morning for 30m or so. Your discs are full of water, and you're more susceptible to injury during this time.