I just changed so that it now comes from the spot futures daily data from Wikiposit (Front month data)
 - http://wikiposit.org/p?futures

I choose Crude Oil, Gold and SIlver and then download the results using the link for the CSV.

I then run it through a formatter script (python):
 - http://pastebin.com/ZX5XZGWM

And then from that script's output I can copy and paste the new data each month into the spreadsheet.


Google Docs spreadsheets have an Insert Charts menu selection.