Andy Edmonds has created a thick client tool for more traditional usability testing (www.uzilla.net).
The lucidity methods are still good and valid and could even be made to work with Macromedia Flash.
Please get in touch if you're interested in an open source javascript implementation of a client side data collector.
Details at http://surfmind.com/lucidity/
Image load time is working, page blur's are dealt with, and a couple of new mouse movement parameters.
A switch to database logging is also coming soon.
The client side tool has been reworked to log data via a IMG SRC tag, instead of the exiting url. While requiring an additional http transaction, this removes the weakness of exiting url tagging which prevents the final page from being logged.
See http://sourceforge.net/project/showfiles.php?group_id=18347
Check the files and documentation areas for details.
After having worked on this project for 1.5 years, I've finally decided to open it up to the usability and open source communities. For immediate release, a entirely client side solution for logging scroll depth and render time, et al., will be distributed. A more detailed 1/5 second system is currently being documented for dissemination.