One of the MTs asked for this information. I thought I'd share it with all of you.
One site I visited said this:
Generally, affect is a verb (action -- doing it) and effect is a noun (the thing that resulted).
Another site I visited said this:
The simplest way into the issue is, If you're going to do it, use "affect." If it's something already done, use "effect."
Yet another site had this:
affect = verb meaning to influence: Will lack of sleep affect your game?
effect = noun meaning result or consequence: Will lack of sleep have an effect on your game?
effect = verb meaning to bring about, to accomplish: Our efforts have effected a major change in university policy.
A fourth site had this:
1) When "affect" is accented on the final syllable (a-FECT), it is a verb meaning "have an influence on":
"The million-dollar donation from the industrialist did not affect my vote against the Clean Air Act."
2) A much rarer meaning is indicated when the word is accented on the first syllable (AFF-ect), meaning "emotion."
In this case the word is used mostly by psychiatrists and social scientists— people who normally know how to spell it.
3) The real problem arises when people confuse the first spelling with the second: "effect." This too can be two different words.
The more common one is a noun: "When I left the stove on, the effect was that the house filled with smoke."
4) The less common is a verb meaning "to create": "I'm trying to effect a change in the way we purchase widgets."
No wonder people are confused.
When you affect a situation, you have an effect on it.
Note especially that the proper expression is not "take affect" but "take effect"—become effective.