You can add a Block Ads button to your Opera toolbar to enable/disable ad blocking globally with a single click. This is convenient when something on a website isn’t working and you want to check if it’s your urlfilter.ini that’s causing the problem.
If you currently do not have a urlfilter.ini you can add the following text into a new one at the proper location:
Remove this line and add ad block filters here.
Other userful features of the urlfilter.ini are the ability to block certain elements that website coders use to impede your use of the functions of your browser.
Some sites like flickr like to give publishers the ability to “disable” saving of images. The key idea being that after the image a person would want to save is loaded another image, a one pixel blank image (usually a transparent GIF), is loaded above it using identical height and width values. This makes it impossible to save the image beneath the “download breaking” image.
All you need to do is add the text below to your urlfilter.ini (may be out of date by the time you read this):
And Site Blocking Too!
Another great thing about urlfilter.ini is that it can do just that, filter any URLs. The main purpose for the regular Joe would be to block unsightly ads but for more advanced users there is the need to filter entire websites. This can also be managed with the HOSTS file, which is a global method, not just for Opera, but HOSTS isn’t flexible and is prone to lagging your internet access if it gets too big (much like urlfilter.ini can actually break Opera if it is too big, making websites load as blank pages).
It’s as simple as adding the base domain to urlfilter.ini to block a website. Blocking certain domains can be useful, for example, if you are an admin at work you may want to block MySpace and Facebook while disabling the use of Internet Explorer (IE being prone to letting less intelligent users infect the host PC with malware). Most statistic grabbing websites that people add to their pages are also blocked by their domain.
The best source for a urlfilter.ini list is at Fanboy’s Adblock. About a month previous to this post the list and its site got a huge update. Now it is updated daily (every 30 minutes, actually) and it’s very likely the best one out there. It also works with other ad blocking programs for firefox.