A recent Salon article by J.L. Bell took a brief look at political Urban Legends documented on Snopes.com. The article's conclusion is that there are more lies told (and spread via email and the web) about President Barack Obama (59) than there were about George W. Bush (17). The fact is even more alarming when you consider that Bush was in office for 8 years and Obama has been in office for only 15 months.
I took the information a little further. It seems that some of the lies told about each President are actually lies that make the man look good (e.g., a lie about some fictional good deed carried out by the President). I broke down the lies into the categories of A) a Right Wing Lie (i.e., a lie meant to favor the right and make the left look bad) or B) a Left Wing Lie (i.e., a lie meant to favor the left and make the right look bad). Next I extrapolated the 15 months of Obama data into what it might look like over an 8 year administration. (I know this is not scientific, it's merely an exercise in curiosity.)
Here is the result: