As a general rule of thumb, ideal ad placement lies in a region balancing the left to right (emphasis towards the left), and top to bottom (emphasis towards the top) portion of a page. Article based pages are an exception, as placing ads directly below an article can lead to a greater number of readers clicking through.
The number of ad units you choose to display can also affect ad performance. While some sites perform well using the maximum 3 ad units per page, it's important to maintain a balance between content and ad display -- the optimal number of ad units per page varies for different sites.
As you probably can tell, I am not exactly following this rule for several reasons. I did consider placing my side bar on the left, but I have found that it can potentially slow down a web page (unless you have two sidebars of course).
Although moving the ads above may help, although I am going to have to do some "htmling" in order to make it work (last time the site looked bloated). Cheers!