1.
put the Ritalin_Public.py file to a safe location
like your maya scripts folder

2.
open or create a userSetup.py
OSX: /Users/YOURUSER/Library/Preferences/Autodesk/maya/2009/scripts/userSetup.py
WIN: C:\Documents and Settings\YOURUSER\My Documents\maya\2009\scripts\userSetup.py

3.
in the userSetup.py put the link to the Ritalin_Public.py file
eg:
execfile ("/Users/Shared/Autodesk/maya/scripts/Ritalin_Public.py")

4.
safe file and restart maya

you should get a new pull down menue "ritalin"