A funny thread at WebmasterWorld shows a good intentioned member saying that he clicks on Google AdSense ads whenever he sees them to support the publisher. But he did not expect the response from the other Webmasters at the forum. Pretty much all of them shot him/her down as it being unethical to click on those ads, since it is costing the Google AdWords advertiser money.
Here is is word for word...
whenver i visit a website with adsense, i would give a click to the adverting firstly: because i think the webmaster provides some useful information to me, i should give him something in return. What's your choice in such occasion? :)
That's not support that's stealing from the advertiser. Your argument amounts to idealism without the sentry of logic.
Bottom-line, just click on ads, if you are interested in the ads.
Forum discussion at WebmasterWorld.