I just wanted to share my experience installing the MySQLdb module on my laptop, which is running Mac OSX 10.6.7 and python 2.7.
I had a couple of obstacles:
1. I had to download and install the package setuptools: http://pypi.python.org/pypi/setuptools#files
2. Then I was able to properly install MySQLdb, but when I would try to import it for use, I was getting an error associated with locating libmysqlclient.18.dylib. The solution I chose was to add the following line to my .bash_profile:
Although I found reference to multiple other solutions online. Hopefully this is helpful to others that run into the same problem.