My site takes more than 7 secs to load - http://www.webpagetest.org/result/120518_Z3_7KG/
Site hosted on dedicated Quad Core 8GB RAM server.
WP Total Cache and MaxCDN is enabled.
Query cache is also enabled in MySQL
My host suggests that since the site more static with less CPU consumption APC is not required and hence not enabled.
I surfed the forum and actioned the MySQL cache and APC measures.
What can I do to reduce the load time ?
Your back-end looks like it is performing fine. It took < 100ms to generate the page (the F for the first byte time is because of the redirect to the www page). Here is a test of the www page directly: http://www.webpagetest.org/result/120518_YK_63acf2056829407066bee990419ee447/
It looks like you are still serving some CSS from your main domain (and your main domain is set to not allow for keep-alive connections).
The Digg Digg plugin looks like it is using blocking scripts for all of the social buttons. You should see if there is an update or go back to the author to ask them to use the async versions instead.