As kids in the late 60s / early 70s we were told “Don’t say OK, it’s rude.” So you generally responded with many other appropriate words.
Did that answer your question OK? 
Here’s what OED says:
Unlike all right, it’s used as a verb and noun, but if it were suddenly banned, people could easily start to use “all right” in those ways, too.
The most frequent use of “okay” is as a discourse marker, to stop negotiation of a topic and initiate a new proposition.
A: So let’s have the government start by setting an example. [proposal]
B: Okay. So what you are saying, it isn’t one way or another. [assessment of proposal]
In this usage, by far the most common, it doesn’t mean “yes,” or “I agree.” It just means, “I’m ending the proposal, and now I’m going to do something with it.” All right is used pretty much in the same way.
Yeah, good point.
Yes it is the accepted etymology, but it wasn’t coined by an illiterate President. From the Master:
http://www.straightdope.com/columns/read/503/what-does-ok-stand-for
23-skidoo!
Very well?
Ayup?
Fuckin’ A
Incidentally, here is a list of all the articles by Allen Walker Read published in American Speech:
Allen - Search Results Walker Read issn:0003-1283&qt=owc_search_art&fq=dt:art
If anyone is interested in reading the six articles (from 1963 and 1964) in which he explains the origin of “O.K.”, you can find them listed there. I’m not sure how you would then go about getting hold of those articles though. I assume that you would have to go to a university library with all the back issues of American Speech (on microfilm or some such).
That’s the fact, Jack!
Amen to that.
“Right on”
“Boss”
Certes