What's the order/meaning of XOXOXOXO?

I was under the impression that it meant "Hugs and Kisses" in that order. Yesterday someone told me they thought the Xs were the kisses...which would be backwards....Who knows the order for 100% sure? Also, for 10 points, how did this tradition start of writing XOXOXO on the bottom of love letters.
Update: Lee T ---> That's what I thought but it seems you and I are in the minority.
Update 2: Melabone has the answer that agrees with one website that I visited. It said that x could mean kiss in one case and hug in another case and vice versa for the O.
Update 3: Ness and Scott D have the most comprehensive answers and though I still don't have a good answer for why the XOXO was reversed if the X means kiss (from ancient history) , I chose NESS for the best of the most comprehensive answers. Thanks to everyone for their answers!
Update 4: ...Interesting....I went to give Ness his 10 points for the best answer from me but the page doesn't give me any choice to do so....I will check back later to see if the option pops up.
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