FactCheck.org looks at the central policy attack in McCain's new ad and declares "that's false." It turns out that despite McCain's claim, Barack Obama does not support raising taxes on electricity.
So which campaign is lying more than the other? Hmm. How about let's take a look at the FactCheck.org home page. I took this screen grab at 11AM Pacific time:
The stuff highlighted in yellow are attacks from the McCain campaign or its surrogates.

The one non-highlighted attack is from Planned Parenthood. All of the highlighted attacks with one exception are from McCain's own campaign.
© Jed Lewison