I'm finding that my VPS (linodes) DNS servers are really slowing my website (phpbb) down when users are posting.  I found this by watching the php-fpm pid with strace.

So i have replaced the linode name servers with google's nameservers by editing
/etc/dhcp/dhclient.conf
and adding
prepend domain-name-servers 8.8.8.8, 8.8.4.4;

and then restarting network services:
service networking restart

But for some reason the linode one is still there:
adrian@wasp:/var/www$ cat /etc/resolv.conf
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
nameserver 8.8.8.8
nameserver 8.8.4.4
nameserver 74.207.241.5
search members.linode.com

How do i get rid of it completely so i can just use google?