perfect for piriformis
I've had a tight, painful piriformis for weeks and this pillow is perfect for that.  It's small and has a hard knob-like thing in it that pushes into the piriformis to help release the tension.  Sitting on a baseball works too, but it's nice having the little cushioning around it.  And the pillow never rolls away from me either, so it's worth the money if you have a really tight piriformis.  My sciatica has been a lot better since getting this pillow and relieving some of that piriformis pressure.
Rating: 5 stars