These days, I look like this:
It's beautiful and I'm a happy pregnant woman, so what I'm about to say is not meant to be a complaint. That said, at 38 weeks there is just a lot of weight to carry around. My back, calves, hamstrings, and especially my hips get very tight. Sometimes I find myself at 3am stretching at the foot of the bed. Prenatal yoga is the solution! I find that if I do about 30 minutes every 3 days or so, and do some walking in the interim, I stay fairly comfortable.
At the risk of sounding like a commercial, I'm going to endorse the DVD I use. For Christmas my husband gave me "Prenatal Vinyasa Yoga with Jennifer Wolfe." I had read reviews of it online before asking him for it. I was afraid of getting a DVD that was, well, frankly, lame. The Jennifer Wolfe DVD is for people who have done yoga before. It's rigorous enough that I think I'll continue to use it after the baby is born. It's also nice in that it demonstrates alternative poses for women in various stages of pregnancy.
My due date is two weeks from today, so it could be any time now! Stay tuned.