As an additional response to designing with both advertisers and users in mind, I defer to Darren’s (Problogger) post on ad position tactics. Check out his original Ad placement:

And the revised layout:

The simple change contributed to a 40% increase in earnings.
To quickly implement this on your site, I recommend the WhyDoWork Adsense Wordpress Plugin. It dynamically puts ads your posts. It even has time-based Ad showing. You can opt to show certain ad formats only after a certain date.
Basically, you can automatically place your ads anywhere with the plugin. Pretty cool.
Golden Triangle gains Higher CTR's for Ads | BusinessGeeks 8:52 pm on May 21, 2008 Permalink
[...] also outlined his little experiment about changing ad positions which was also further explained in Where To Put Adsense Ads And A Dynamic Ad Placement Plugin by Jozzua. In Darren’s article he illustrates the before (left) and after(right) ad [...]
BusinessGeeks » Blog Archive » Golden Triangle gains Higher CLICKS for Ads 4:23 pm on August 5, 2008 Permalink
[...] also outlined his little experiment about changing ad positions which was also further explained in Where To Put Adsense Ads And A Dynamic Ad Placement Plugin by Jozzua. In Darren’s article he illustrates the before (left) and after(right) ad [...]
Golden Triangle gains Higher CLICKS for Ads | BusinessGeeks 6:35 am on September 16, 2008 Permalink
[...] also outlined his little experiment about changing ad positions which was also further explained in Where To Put Adsense Ads And A Dynamic Ad Placement Plugin by Jozzua. In Darren’s article he illustrates the before (left) and after(right) ad [...]
Golden Triangle gains Higher CLICKS for Ads - BusinessGeeks 6:24 am on March 18, 2009 Permalink
[...] also outlined his little experiment about changing ad positions which was also further explained in Where To Put Adsense Ads And A Dynamic Ad Placement Plugin by Jozzua. In Darren’s article he illustrates the before (left) and after(right) ad [...]