It is not OK.
It is okay.
**
It is not alright.
It is all right.
***
It is not wanna, gonna, coulda, shoulda, woulda.
It is want to, going to, could have, should have, would have.
(The only exception to these should be made in dialogue, or if you are planning some massive narrating going on, but then you should still do it with strength and throughout the entire piece.)
***
It is not towards.
It is toward.
***
It is not backwards, forwards, afterwards.
It is backward, forward, afterward.
***
It is time already to get to work, where I should have completed many other things before the day ends. ttfn!!
Adrian J. Smith 
I must disagree on the first one. The origin of the phrase “okay” started with the expression “oll korrect”. Seems there was a passion for humorous misspellings in the mid1800s. Though in truth I would use “okay” in that situation, too.
http://www.straightdope.com/columns/read/503/what-does-ok-stand-for
These are really interesting and complex. As Graham said above, OK was originally correct, but AP style now has it spelled out. For the most part, I go with spelled out, even in dialogue. But “alright”? Man, I am going against the grain here, but I’m a fan of “alright” as one word. That’s how people say it, and for the most part it’s only ever used in speech or deep narration anyway.
I’d be in a fix if I ever saw the shoulda/wouldas, though. Though I guess that falls in the same range as “damnit,” which is my favorite spelling of the curse.
I was all fixin’ to be upset when I saw “towards” in Margaret Atwood’s newest novel but apparently the lack of an s is an Americanism, and it’s cool with the Brits and Canadians. Interesting, no?
It is!! Totally. British spelling is insane. The “alright” is British and it isn’t always said as one word. Dialogue affords a lot of flexibility, but these are all ones I’ve seen in narration and exposition–and recently.