Peter Stevens had 2003 ZZR600 (originally a ex-Southbank BMW loaner) on sale a while back with them fitted. They were mounted on top and inboard of the left-hand grip. Large knob on top big enough to adjust while wearing gloves...
Pretty neat setup, and as some of the posts mentioned, it may be better to go for a model you can adjust the heat.
These ones are fixed, as far as I can tell:
http://www.maw.com.au/cache/item-2020public.html?cache=no
These ones wrap around and don't seem to be adjustable either:
http://www.mcas.com.au/_product.php?section=1&prodid=2567
More:
http://www.mcas.com.au/_product.php?section=1&prodid=2569
http://www.mcas.com.au/_product.php?section=1&prodid=1459 (no pic)
http://www.mcas.com.au/_product.php?section=1&prodid=2568 (adjustable)
These ones look ok (but they're dearer):
http://www.bikebiz.com.au/shop/en-us/p_2930.html
They also have two others:
http://www.bikebiz.com.au/shop/en-us/p_2931.html
http://www.bikebiz.com.au/shop/en-us/p_3984.html
BTW> It was 1 degree up here that morning, I didn't think it was that cold, however, I'm only going 15km and it's all over in less than 11 minutes

HTH