Guy Senior Portraits - Posing

I've been asked to shoot senior school photos for my male cousin - I just did some shots for his younger sister here: http://bit.ly/hGbny
I've never posed a guy before and would like to get any pointers from the pros. Guys this age are typically not very photogenic, a bit awkward, and concerned with looking "cool." I anticipate a subject who isn't too excited to be in front of a camera and I think that's going to show through in the photos.
Any sample galleries would be helpful too - thanks in advance for the tips..
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I've never posed a guy before and would like to get any pointers from the pros. Guys this age are typically not very photogenic, a bit awkward, and concerned with looking "cool." I anticipate a subject who isn't too excited to be in front of a camera and I think that's going to show through in the photos.

Any sample galleries would be helpful too - thanks in advance for the tips..
`S