The SEOmoz Blog points out two heat map tracking software solutions.

CrazyEgg (I think Rand already talked about it), which is simple, easy to use and cost between 0,33$ - 0,80$ / 1 000 visits. I am not sure how deep the metrics are behind it. Has any of you tried it? It is worth it?

ClickDensity is the other one I found and seemed to offer wider and more detailed statistics. Setup seems to be a breeze. Costs seem lower per 1 000's.. They offer some nice A/B test splitting, allowing you to change snippets of html code as you like to compare conversions.

And of course, Google Analytics offers some primitive heat map capability in the form of their 'site overlay' report (see screenshot below).

site-overlay.png