Science Buddies: "Ask an Expert"

I am participating in the New Jersey 2007 Chemistry Olympics. One of the events is to find the percent fat composition of milk. It is not neccesarily cow's milk, and is may possibly diluted. Assuming it is homogenized, how would I go about finding the percent fat? I'd like to consider myself strong in the sciences, but this is unfamiliar territory. Please respond via email with any comments or suggestions

*There are no restrictions on devices or materials used, but I'd prefer a solution with standard lab materials including a centrifuge.*

I'm not a chemistry expert so I would keep checking back to see if anyone has any other ideas.

Also, I'm not sure about the policy on replying to personal e-mail addresses so I need to post here.

Apparently, there is alot of prior work in this area. I just now went to Google and entered the following keywords: "milk fat method centrifuge". Most of the links that popped up were about various methods for separating the fat from milk.

The first one:
http://jds.fass.org/cgi/content/full/88/10/3377

Looked like it would probably be a pretty good place to get some ideas.