type "internalVar -usd;" no quotes into the MEL script box in the bottom left of Maya and hit enter.
Then pull up the script editor in the bottom right of Maya to view the path.
SPECIAL NOTE:
Apparently when you install MayaBonus2010 Tools your scripts path might get changed and even if you run the command above it will not tell you the correct location of your scripts folder. If you press the scripts box, very lower right of the screen in Maya. You can then select file>load script, and this should show you the new folder.
In my case E:/MayaBonusTools2010/scripts
That was a royal pain to figure out. It coudln't seem to locate my scripts folder anywhere...
If you come across any easy way to locate your Maya scripts folder please let me know!
If you come across any easy way to locate your Maya scripts folder please let me know!