I've always had the sidebar ads but just added the horizontal banner today. http://www.pccurb.com/ thanks.
I would place a rectangle above the search, which will move your whole sidebar section lower. Don't blend it. Use a color that corresponds with your template and stands out. Make the corners round. Also, get rid of the feedburner stats.
They take your space for more important things and distract your visitors. You need to have all the important stuff above the fold, because many users don't scroll.
I agree with JohnS0N. I would use feedburner stats if I had thousands of readers, or something like that. If there aren't many it doesn't look good for the visitor. That PC setup looks good btw, similar to mine actually.
If you're talking about the one up the top right I just added that (JohnS0N's advice), and am trying to get it right.
You would need to make that a rectangle and extend your sidebar. The ad doesn't fit in right now. And after you do that you should test this placement out; http://img230.imageshack.us/img230/9871/adsense1yn6.jpg EDIT: In the picture I said width, but I actually mean height. The ad you currently have above the content (468x60) could be moved below the first post or you could have a rectangle place inside the post to the left and WRAP the text around it.
I know. Design wise, I think it looks a bit out (in terms of the width). You should target search engine visitors for higher CTR and when they come to the landing page, you would want them to see the ads embedded in your contents.