I've been trying this out, and it is great.
It's not really that much use if you have a bog standard text/menu site as the navigation is predictable anyway. But if the page contains multiple links scattered around the place then it is ace. I tried it out on a couple of sites and the results were amazing.
After a couple of hours on
http://www.jackandjill.ie I got the following....
Many thanks for the heads-up.