What is the pronunciation of the possessive words that already end in s? [duplicate]

Possible Duplicate:
When did it become correct to add an ‘s’ to a singular possessive already ending in ‘s’?
Which singular names ending in “s” form possessives with only a bare apostrophe?

My name is Greg — this is Greg 's post.

If my name ended with an 's', I am aware of the proper apostrophe usage (James → James'), but how should this be pronounced?

Phonetically, am I Jameses best friend or James best friend?

James' [z] best friend

sounds better. If this is the right form, then according to this thread, [z] would apply:

In the suffix -(e)s, indicative of the plural of a noun, the possessive case of a noun, or the 3rd. person singular past tense of a verb, the -s is read:

• voiceless, [s], when it comes after a voiceless consonant...

  cats, tracks, boots, walks, etc.

• and voiced, [z], when it comes after a voiced consonant or a vowel.

  dogs, cars, skies, keys, days, etc.

The pronunciation of the suffix "s" added for a possessive can have three forms: [s],[z] or [iz].
The rules for pronunciation are the same as for the plural. You have:

• [s] Nick's Pope's Stuart's (voiceless consonant before s)

• [z] Laura's Greg's Tom's (voiced consonant or vowel before s)

• [iz] Travis's , Buzz's , princess's, coach's (when the singular words end up in "s","z" or fricatives such as "sh", "ch","ge")

Source: The pronunciation of English, Charles Kreidler

Note: Only the singular words add the possessive "s". The absence of possessive "s" after a plural is for the ease of pronunciation, as exemplified below.
If a man with two mistresses wanted to speak of things he'd given to both of them, I'd advise him to drop the 's, rather than try to pronounce mistresses's with a straight face!
Okay, some hearers might then think he only had one mistress. But that might even be an advantage - if one of the mistressess overheard him talking about the gift[s], for example.

The possessive s is dropped from writing in many contexts, but there's no universal agreement about exactly which. Take James's, where quite a few people drop that last s in writing. But very few people would fail to pronounce it - especially not parents of James! Unless maybe if they're talking about James's essay, for example. Even then I would think it slightly odd to drop the s because it's not that hard to say. YMMD, of course.

However, if the possessive is not added, so we have only James', the word is pronounced (in careful speech) exactly as if it were by itself. In other words, the possessive doesn't make a difference.
(the above answer was merged from the ones provided by FumbleFingers and Bogdan Lataianu)

I am not an English major, but I'm quite literate, and literal as well. My son's name is James. I am far from ordinary, and have never been, so this comes as no surprise... "very few people would fail to pronounce it — especially not parents of James!"

I do not pronounce possession with regard to my son's name ending in an 'iz'. Someone, somewhere, recognized that there wasn't to be an s after the apostrophe, because there's already one s there, and that if your son's name is James, putting an iz on the end of it is like nails on a chalk board.