The tools in this page are obsolete
FireFox Add-On extension
Create webpage heatmaps directly from your FireFox.
Download the Feng-GUI heatmap extension for FireFox.

sample heatmap of firefox homepage
Feng-GUI ViewFinder extension page at FireFox
Bookmarklets (or Favelets) are tiny javascript snippets, which you can save as a bookmark, a favorite or within a webpage.
They are an easy way to heatmap the current page with one click.

example 1:
The following javascript heatmap the current page.
javascript:void('' + encodeURIComponent(window.location)));

example 2:
You can also place this javascript inside a hyperlink.
<a href="javascript:void('' + encodeURIComponent(window.location)));">heatmap me</a>

live example (of example 2) heatmap me