From Adblock Plus:
Adblock Plus for Android blocks all annoying ads on your tablet or smartphone! NO ROOT REQUIRED! It blocks intrusive ads from reaching your phone, including most in-app ads and those you would normally encounter while browsing. when browsing with your mobile device similarly as it does on your desktop.
The most popular browser extension ever is free on Android Download Adblock Plus for Android start benefiting from increased browsing speed, enhanced privacy protection and less annoyances!
Adblock Plus for Android is a proxy server solution blocking:
*all mobile ads in your browser
*display advertising and much more.
Besides that an option to blog malware and tracking is included.
PLEASE NOTE: Adblock Plus might have limited functionality, depending on the Android version you are running and whether your device has been rooted:
Rooted: Blocks ads over WiFi and 3G
Non-rooted with Android 3.1 or later: blocks ads over WiFi
Non-rooted with Android 3.0 or earlier: some manual configuration is required.
Also, Adblock Plus for Android does not allow ads to be blocked on SSL encrypted websites.
Adblock Plus is an opensource project. Hundreds of volunteers are contributing to the development and maintenance of over forty continuously updated filter lists in more than a dozen different languages.
The Acceptable Ads initiative ensures that all annoying ads are blocked while supporting websites fully reliant on advertising, which is still most of them.
Please note that Adblock Plus will probably become the highest data-using application on your Android device. However, this is only because it needs to filter data to ensure that the ads can be blocked. Adblock Plus is actually only using a fraction of the data shown on your device.
Adblock Plus is also available for Mozilla Firefox, Google Chrome, Opera, Safari and Internet Explorer, not to mention on the Firefox mobile browser.