The best part of Adblock is that you can set your OWN site to block ads (if you're afraid of generating false impressions and clicks, that is), but see ads everywhere else, or vice versa. It's very nice indeed.
The best way how to block Adsense Ads on web is by using Firefox browser and AdBlock Plus plugin. Then click on menu Tools - AdBlock Plus Preferences and click on "Add Filter" button. Input this URL as new filter: http://googleads.g.doubleclick.net/pagead/* and http://pubads.g.doubleclick.net/* It's works 100% for me!!! Try it.