Some details of my machine and installed packages before proceeding further:
Mac OSX version: 10.6.6
Python version: Activestate Python 2.7.1
wxpython version: wxpython 2.8 (uses Carbon API hence limited to 32-bit mode arch only)
I installed wxPython2.8-osx-unicode-py2.7 from wxpython website using their .dmg installer file. This package uses the Carbon API and hence is limited to 32-bit mode only. I have to write my applications using "arch -i386" in order to import wx, and due to this limitation I am unable to import certain other packages likes "MySQLdb" which are not available in 32-bit mode. So, my best option is to uninstall wxpython 2.8 and install wxpython 2.9 because version 2.9 uses Cocoa API which has both 32-bit and 64-bit support. 
I don't know how to uninstall wxpython2.8 on my Mac OSX. Can anyone please help me?
If you look in the .dmg for wxPython, there is an uninstall_wxPython.py unininstall script. Just drag it to your desktop and run python ~/Desktop/uninstall_wxPython.py in a terminal.
How to uninstall wxpython 2.8 on Mac OSX 10.6