I'm selling advertisement spots on my Microsoft Zune blog and information site: ZuneUser.
The site is ranked 2nd when you search either "zune" or "microsoft zune" on Yahoo.com and the hits continue to increase as the Zune nears launch.
http://zuneuser.com
You can get the banner ad spot on front page (where Google ads are currently), a button on the right hand sidebar, or a text link on the sidebar.
Prices are negotiable. Please state if you are interested (and your offer) by posting here or contacting me otherwise.