so obviously i didn't get a chance to post a simplified version of how to use AMD GPUs for SETI@Home last night. and i probably won't have time to do so until wednesday or later due to a very busy work schedule. that said, i think i can make things a bit simpler than the way they're explained in that overclock.net forum thread. since the release of the Lunatics installers (starting w/ v0.37, the most current being v0.40), we no longer have to manually download the appropriate applications, or manually create the associated app_info.xml file, or place them all in the appropriate directory. the Lunatics installer allows you to pick and choose which apps you want to use (from a list of various CPU & GPU apps), places them in the appropriate directory, and generates an app_info.xml file containing the necessary code for the selected apps for you.
the only intimidating part from here on out would be to edit the app_info.xml file for various reasons, the most common of which would probably be to allow more than 1 GPU task to run simultaneously. so if you're content w/ running one task per GPU at a time, then you don't need t edit anything in the app_info.xml file and you're good to go. if you would like to improve GPU load and/or crunching efficiency by running 2 or more tasks simultaneously, then you have to find the <count>n</count> line in that application's code section in the app_info.xml, and edit the value accordingly. the default value is 1, which corresponds to running 1 task at a time on the GPU(s). n = 0.5 corresponds to running 2 tasks simultaneously, n = 0.33 corresponds to 3 simultaneous tasks, as so on and so forth.
the only other things to remember are your basic project and web preferences. in other words, you want to make sure the project is setup to use the GPU (from both the server end via your web preferences, and from your own end via the BOINC manager preferences). also, if GPU computing is the only SETI@Home crunching you plan on doing, make sure your web preferences aren't set to use the CPU.
i'll post up in a few days w/ more detail...