Below are a few recommendations on how to block ads within various browsers.

Firefox
  - AdBlock Plus - Installed as an add-on
Internet Explorer
  -  "InPrivate Browsing" - this is a "tool" in IE
  - IE7PRO
  - Simple AdBlock

Chrome
  - AdBlock for Chrome - Installed as an add-on

Opera
  - Utilize Opera's built in content blocker (similar to IE's InPrivate Browsing tool)