I haven’t yet… but I have some ideas for testing and product design processes that would benefit from eyetracking.
I tried to get some academics (who had access to the equipment) interested in doing some eye-tracking studies of ecommerce and web-based applications a number of years ago, but I wasn’t able to drum up enough interest to get it rolling. I’m guessing that eye-tracking machines are much cheaper and more readily available now? How hard is it to get access to one, how much do they cost now, etc?