The California-based correspondent and producer has made a name for himself as a solo journalist, or 'sojo', travelling the world with a laptop, satellite phone, sleeping bag and handheld reporting equipment.
He has been hired by the web giant to cover all of the world's armed conflicts in one year, using the web to 'deliver stories via a five-finger multimedia platform of text, photography, video, audio and interactive chat'.
'Yahoo! News, published Sites' first reports from Somalia this week, including an interview with a mother whose daughter was crushed to death by a falling US helicopter.
The material was held back for a week 'for security reasons', however, according to Yahoo! News director Neil Budde.
"I will report from the field solo, as I often have over the last five years, but will be supported by my 'Mission Control' team based in Santa Monica, California," wrote Mr Sites on his blog.
"Our first-year goal is ambitious - to cover every conflict in the world within one year. The London-based International Institute for Strategic Studies is currently monitoring 31 armed conflicts, with 15-20 seeing recent military action."
Mr Sites began adding personal reportage to a blog whilst working for CNN in Kuwait in 2003, but was barred from blogging by the news network.
He later returned as a freelancer for NBC, which allowed him to continue blogging and for which he last year recorded some of the most explosive images of the Iraq conflict – US Marines appearing to shoot in the head a wounded insurgent during the struggle for Fallujah.
Mr Sites said he intends to return to the city for In The Hotzone in November.
He will publish raw video material, photo slideshows, audio packages and textual reports to the site and will edit media on an Apple Powerbook. Readers can also respond to dispatches and can participate in chats with Sites.
Yahoo! Media Group leader Lloyd Braun told The New York Times: "If we execute this the right way, it is a great first step to show people how we can present content in a different kind of way than television, one that embraces the qualities of the internet."
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