Great for both the gym and lounging around, these yoga pants sit on top of your belly so you'll be comfortable no matter what activity you are doing. (health.com)
Place a heating element, like a hot water bottle or heating pad, on top of your belly. (mindbodygreen.com)
Something fun to try: when your baby is being very active, lay a light object such as a paper plate or paper napkin on top of your belly, while lying down. (pregnancy-baby.com)