My heartburn is wicked evil!!! I found that a decent yogurt stops it in its place, though. Admittedly it's somewhat of a short term fix - it only lasts about 2 or 3 hours - but its immediate and i can get these mini-4oz cups from our local Trader Joes market, which are just enough to quell the fire in my esophagus without causing me to hate on yogurt from over-consumption.
I'm not going to vouch that its "this or that" in the yogurt cup that makes the heartburn vanish, but the stuff I buy is loaded with live active cultures. It's also organic. I don't know if either of those things factor into the cure, or if yogurt is just adept at balancing out the pH in the stomach, but I swear by it as a heartburn cure and haven't needed to take anything else!