which is correct, "waiting on" or "waiting for"?

In the sense of the example you gave, either can be used to convey the same meaning. However, I would recommend that you use "waiting for" in formal writing.

"Waiting on" can also be used to describe what servants/servicepeople do, such as how waiters at restaurants "wait on" diners, by taking their orders, serving their food, etc.

"Waiting for" is the proper term. "Waiting on" is another case of improper use of the language going mainstream, based on the predominance of usage. I am definitely not an English Language scholar, but this is something I remember from grade school. I will continue using "waiting for". This begs the question - does the predominance of incorrect grammar in our American society justify its mainstream acceptance? I'm not judging, just asking. I'll be waiting for your responses!

Either one.

Yes. First of all, of course universal health-cover sucks. That is why we in Western Europe have it. We think, hmm, our healthcare system sucks. I know, lets keep it. I guess that is the same with Japan and Canada as well. Second, Obama is not going to bring in universal healthcare. He wants to make insurance more available to all. FACT - the USA spends more on healthcare PER PERSON than any other nation on the planet. FACT - the US has higher death rates for kids aged under five than western European countries with universal health coverage. That means that a dead American four year old would have had a better chance of life if they were born in Canada, France, Cuba, Germany, Japan etc, all of which have universal health coverage.

I notice that "wait on" is the preferred usage in Scotland whereas, "wait for" is used in England. Possibly, migrants took their preferred usages to the U.S. where they persist to this day owing to historic migration patterns. Just a thought. (I await further comments. )

I was told by my Mom (a teacher) that the best way to remember when to use which is "You wait ON the platform FOR the train." My Dad added that if you are waiting ON someone, they are probably in pain from your weight.

waiting for a delivery would definitely sound much better.

waiting on = waiting on the chair. (physically)
delivery = abstract in this case.

Waiting is the correct term

http://www.yourdictionary.com/for
http://www.yourdictionary.com/on

You should go to this link it is very useful to use. You might get a better understand what correct word to use.