Since this was posted, I have figured out the problems with PEBL on OSX and uploaded a new fix. This new fix will work on OSX 10.7 and newer. Here is a screencast for the new version, the older screencast is still available for users of OSX 10.6, and those who want to install the BST.
Some folks have reported troubles installing PEBL on a mac. It actually does work, but there is an annoying interaction between OSX crash reporting an a mostly-harmless crash of PEBL. Below is a video that walks through installation, as well as how to install Esposito et al's Bivalent Shape Task--a non-linguistic interference task similar to the DCCS, Simon, and Oddball tasks.
The video shows installation on 10.9, but it should also work down to OSX 10.7, and maybe lower.
For a little more detail, PEBL 0.13 has a problem when it tries to exit such that it will crash before it completes its shutdown. OSX detects this and puts up a crash detection dialog. The basic workaround is to choose Ignore when it does this at the end of running, and reopen when it does this when you are trying to run the launcher.