As I understand it (via the "Windows" experience) this can be done by adjusting the hosts file.
In /etc/ are three file hosts, hosts.deny and hosts.allow
I can't save the file, no rights.
And another thing, I can not understand why in the line three entries, not two as in Windows
[internet address] [domain name] [alias]
127.0.0.1 vkontakte.ru will be enough? or hvatit records vkontakte.ru in the file hosts.deny?