The AVR Studio simulator is great at logging the port states to a text file, but it's not such a user friendly format if you want to visualise whats going on...
So I've written a small utility to give a graphical "logic analyser" style display of the simulator log files.
A file download link and GPL source code can be found at http://www.dresco.co.uk/LogAnalyser
It's a first revision, but I'm pretty happy with the functionality so far. One obvious improvement would be to follow the log file in real time, or even to get the data directly from Studio as a plug in, but that will have to wait for another day ;)
Finally, I just wanted to get the US spelling of analyzer in this post as well (to help with any searches from there)