Probably within the last 6 months, but definitely within the last
year, I saw a news story about a barista who "paints" portraits in the
tops of cappuccinos by mixing the light-colored foam the dark
espresso.

For an answer to this question I just want a link to an online news
story that includes a photo of the portrait.

Hello Cope360,

It took a while to find an actual article with art work created in the
cup as opposed to simply using lighter and darker coffee as water
color paints.

I first found this image which I felt put me on the right track.
An image from an Italian coffee website:
http://www.ecm-espresso.it/images/news02/Blue.jpg
search theory: Google images search engine keywords "coffee art"


Working from there and realizing "coffee art" pulled way too many
water color types artists, I went with a different search and found
what I hoped was the article, instead it was an ad for a book.
Gilkatho fine coffee supplies:
http://www.gilkatho.com.au/shop/Scripts/prodView.asp?idproduct=148
search theory: Google search engine keywords barista coffee art


Finally, a brainstorm, different words again but this time...GOLD!!!

I think this is the article you are referring to, It is an interview
with barista, Mark Christman.
Latte Art by Lura Lee:
http://www.ineedcoffee.com/02/12/latteart/
search theory: Google search engine keywords article designs latte foam

This website also came up, altho it is more of a guide then an
article, it details how to make some of these wonderful designs.
Milk Frothing Guide - Latte Art Guide by Jim Schulman:
http://www.coffeegeek.com/guides/frothingguide/latteartguide
search theory: Google search engine keywords coffee milk art

Other interesting latte art sites:
http://www.dairyfarmers.com.au/internet/s14_crema/latte_art.jsp
http://www.coffee-house.org.uk/latteart.html
http://www.intelligentsiacoffee.com/rs_store_latte.html
http://www.espressovivace.com/archives/9412ct.html
http://www.latteart.org/latteart.htm

Please feel free to ask for clarification before rating this answer.
Thanks and enjoy,
Mother911-ga

Thanks, Mother911.  You didn't get me the exact answer I was looking
for, but you got me so much closer than I was able to get on my own
that I am going to accept the answer.  I added the keyword portrait to
the search I found the following blog post immediately.  It has the
photo and story I was looking for.

Google: latte art portrait

http://www.boingboing.net/2004/04/25/latte_art_part_two.html

There is also a link there to the original article in the Herald Sun,
but they don't have the article online anymore.