On April 9, 2010, Matt Cutts an Engineer for Google reported that Google has incorporated site speed in search rankings.
Try a speed test of your website and compare it against some of your competitors with this tool recommended by Google.
Here's one we just ran - because getting an answer fast makes our customers happy, making our website fast makes us happy too!
Speed test conducted on December 3, 2010
Speed test conducted on April 23, 2010
Speed test conducted on November 11, 20 (11/11/11)!