I can relate to this, Schappy!  My sleep doctor had great suggestions on this when I was having trouble.

1. Make sure your environment is suitable for sleeping (low or no natural light), low stimulation (no TV in bedroom!).   Make sleep the primary purpose in your bedroom (eg, no taking work to bed, reading to relax, not stimulate the mind.)
   
2. Establish a regular bedtime and wake up schedule.
3. No exercise within 1-2 hours of bedtime.
4. If you awake and are lying there unable to get back to sleep, try relaxation techniques such as deep breathing, even meditating (not true meditation lying down, but to calm your mind).   If after 15-20 minutes you are unable to sleep, you might read something light (not work!) and then try again.

Dr. Mark Liponis at Canyon Ranch wrote about this in his book UltraPrevention. He provides a great summary of his sleep advice here. It includes recommendations on diet, environment and activity. I've tried a few of his recommendations:

- Yoga, my best way to fall asleep is to buy one of those $15 yoga DVDs.  Rodney Yee's are famous. 

- Avoiding email and TV.  Liponis notes and a recent study corroborates that media before bed changes your perception of sleep, i.e. you think you sleep less (even if you don't). 

- Keeping the room truly dark.  I've had enough lights in my bedroom to compete with a small silicon valley data center. Aggressively turning off sources of ambient light (hiding surge protectors, moving computers, etc) and getting heavy blinds really works for me.

I struggled with the stress/sleep monster too but for the most part am past the problem now. Two things I found helpful were 1) I put my desired bedtime and wake-up time into my calendar as recurring "appointments" with alerts. My calendar syncs with my phone so it reminds me of my intention to get my 8 hours. 2) I began practivcing vipassana meditation (AKA mindfulness/insight meditation). I find this extremely helpful for "spinning down" at the end of the day so I can go to sleep in stillness rather than mind-driven stress.

Stress and getting a good night's sleep don't mix. I have the same problem and it seems that my mind wakes me up rather than my body.

If possible, try to stop working all evening. Do something relaxing from reading to listening to music. I also like listening to meditation podcasts on my iPod.

I hot bath and herbal teas can help, too. Also, make sure your room is both dark and cool. When it's so hot outside, sometimes that's tough.