Configuring DHCP / DNS on desktop machines
I think every computer in the world should run its own DNS resolver. It's a matter of performance and robustness. However office machines are DHCP clients more often than not, and DHCP clients tend to rewrite /etc/resolv.conf. So at every install there are things to do.
prepend domain-name-servers 127.0.0.1;
to the dhclient.conf file (strangely enough in /etc/dhcp3).
NB: the line generally already exists, but is commented out.