The ad block extension is a little different than what we're used to in say Firefox or IE 8.
Here's one method that I've used:
Adblock+ For Opera 10 Browser
Though this isn’t a Adblock+ plugin or any addon but it sure does what you need. First of all, open your opera browser and open any webpage (this page) and follow the instructions. Now, click on
Tools –>
Advanced –>
Blocked content which allows you to block webpage content from the website.
I also use the following which works quite well.
Fanboy's Adblock List for Opera
Main List:
urlfilter.ini save this file into: (Vista/7) C:\Users\"your username"\AppData\Roaming\Opera\Opera\
You have to select "View Hidden Folders" to see the AppData folder.
Fanboy's website URL:
http://www.fanboy.co.nz/adblock/opera/