Verisgn has released it’s Domain Name Industry Brief report analysing the 4th quarter of 2006. It contains some very interesting statistics

of 66,871,556 domains analysed
23% were parked sites
63% had live sites
14% had no website

At the end of 2006 2.1 million .com and .net registrations were added per month growing the total .com and .net registrations to over 65 million. And the total registrations for all gTLDs and ccTLDs  exceeded 120 million for the first time.

The largest TLDs by size .com, .net, .de, .uk, .org and .info