By preventing some ads or graphics from downloading in the first place, web pages will load significantly faster for you, some in half the time they used to.
If you change your mind and want to load a web page in full, simply hold down the option or shift key while the page loads. It is that simple. Option-Command-. (Period) also toggles filtering on and off for your convenience.
Mac OS X 10.3 or 10.4.