Oxford Comma
Oxford University have 'put their foot down' so to speak, and said that in their eyes the correct usage of a comma in a list includes a comma after the penultimate list item.
ie. One, Two, Three, and Four.
(As opposed to One, Two, Three and Four.)
I agree with the Harvard/Oxford Comma and have always used it because that's what made logical sense. The comma seperates items, and a list is read One......two......three......and four, not one......two......three and four. Clearly the 'and' goes with the last item, as opposed to the last two items being mushed together with an 'and' in the middle... Hence the penultimate item should be seperated from the 'and' through the use of a comma.
Having said that, I also know that correct grammar works in mysterious, and not always logical, ways.
eg:
asqui1 once said to me, "Son, when using an inline quotation, or brackets, you should include your period before the closing quote." Though I did not believe him because that seemed illogical (not to mention that he moved to Great Britain where they don't force you to study English towards the end of Secondary School.)
But clearly, a logical person would have said, "It is but logic that if the period is a part of the quotation is should be included within the quote marks, but not prevent the use of a period at the end of the sentence as per usual.". I must say that I do indeed agree with this view.
(I just found a node discussing this at: logical punctuation.)
Now, what about a list consisting of two items only?
One and Two.
Not: One, and Two.
That's what I say anyway. It's an exception.
But it is a fact that I never was too good in english class, and that I no longer study english, so feel free to administer hostile flames via the chatterbox. :)
1 asqui is not capitalised as it is one of few proper nouns in the Engligh language which must never be capitalised -- Thus forcing you to break the "Any proper noun must be capitalised." and "The first letter of a sentance must be capitalised." rules. But that's okay.