Today, as part of our ongoing effort to make the web faster, we’re launching our own public DNS resolver called Google Public DNS, and we invite you to try it out.

Why use Google’s DNS?

The average Internet user ends up performing hundreds of DNS lookups each day, and some complex pages require multiple DNS lookups before they start loading. This can slow down the browsing experience. Google have suggested that using their DNS will speed up internet usage and browsing.

Using Google’s Public DNS for Snow Leopard

• Step 1 (System Preferences):
  Open your system preferences and select the Network panel (it will be in the Internet and Wireless section).
  
• Step 2 (Network preference pane):
  In the Network preference pane, make sure your network connection is selected (Airport or Ethernet) and click “Advanced”.
  
• Step 3 (DNS tab):
  Open the DNS tab in the next panel and add Google’s DNS servers using the “+” button.
  DNS Server 1 (preferred): 8.8.8.8
  DNS Server 2 (alternate): 8.8.4.4

• Step 4 (Delete old servers):
  Delete all your old servers or move them to botton (hold Command + mouse click and move)
• Step 5 (Save work):
  Then just “OK” and “Apply” your way back out of the various dialogs and you should be good to go.
• Step 6 (Testing):
  Test that your setup is working correctly; see Testing your new settings

Setting up Google DNS in Mac OS X is a post from: My MacOS X