Ordered one of these from http://www.shopabsolutecp.com/ Good people...

...and wow, does it do the job. Rode into work this mourning in 44F rain and could not get my shield to fog no matter how hard I tried! Very nice. Pretty comfortable, but my not be for everyone. It has a plastic nose bridge piece so you have to fit it well in the helmet...

alvis

+1 - it works like a charm. I haven't gotten mine dialed in quite right yet to prevent it leaving a red mark on the bridge of my nose and cheeks. I know it will work just fine, I just haven't fiddled with it enough yet. Great product and very cost effective. I think it was about $12 or so if I recall.