This is a great service. Please let me know what you think about my ad placement. I just made a few tweaks on my money saving blog so I think it is pretty good. I guess only time and clicks will tell! http://moneydebtandtaxes.com/
Kat, I would definitely change some things. I have this blog ( http://youngerskinin10days.blogspot.com ) and I find that this placement is the most profitable for me. I do not use link units anywhere on my site(s). Put two large text units (like 300X250 or 336X280) on top and mix one with the text.
I would suggest putting ad units into your individual posts, at the end of the post, rather than in the sidebar. They'll blend in a little better because of the white background and try to get the text to match the color of the text for the post tags, "leave a comment" and "trackback". Also, the horizontal ad unit at the top of the each page seems to get cut off by the sidebar, at least in the browser that I'm using. So the last ad is only half showing. If you do stick with the ad units in the sidebar, I'd try to get them to blend in a little better. The white background makes them stand out a little, but it may be hard to match the background since it has a gradient. Good luck!
It's a good-looking site and the ads are in good placement. But white space on the lower page seems not good-looking.