Well, as for my previous post, just to make it clear, I was referring to making the "Ads by Google" text less noticeable. For example, one page I have, the border is a dark grey and the Ads By Google is black. It's still readable, but it doesn't shout out in your face like some other ad layouts sometimes do. I agree, you shouldn't hide them or Google will cancel you.
This site: http://www.sitemeter.com/default.asp?action=search seems to have removed or hidden the "Ads by Google" text from the google ad to the left. I guess they are a premium publisher and have permision to remove it... I wonder why they have kept the "Ads by Google" on the top ad??
True, yet we make them millions each year too. So it's a reciprocal deal. Both helping the other out.