Fun Fact: How to stop water from boiling over!

So here is a little tip that my grandma taught me: to stop water from boiling over when cooking pasta, add just a little drizzle of oil (olive, vegetable, whatever). This will a) keep the pasta from sticking together (a huge pet peeve of mine) and b) create density in the water so it will not create a mess on your stove. Furthermore, it allows you to keep you boiling water on high heat thus reducing cooking time.

I've read some message boards that disagree with me wholeheartedly (something about adding extra calories - it's less than a teaspoon and then is drained, so, um, get a life) but I have been using this tip forever and have never had any issues.

Have you done this before? What did you think about it?