For efficiently using dnsmasq. Based from http://wizardmode.com/2012/06/apache-php-mysql-dev-on-os-x-lion-with-a-minimum-of-pain/ /Library/LaunchDaemons/com.setdns.plist /usr/local/bin/setdns.sh

com.setdns.txt

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
  <key>Label</key>
	<string>com.setdns</string>
	<key>ProgramArguments</key>
	<array>
		<string>/usr/local/bin/setdns.sh</string>
	</array>
	<key>QueueDirectories</key>
	<array/>
	<key>UserName</key>
	<string>root</string>
	<key>WatchPaths</key>
	<array>
		<string>/Library/Preferences/SystemConfiguration</string>
	</array>
</dict>
</plist>

dev

# /private/etc/resolver
nameserver 127.0.0.1
domain dev
search_order 1

dnsmasq.ini

# /usr/local/etc/dnsmasq.conf

address=/.dev/.sbx/127.0.0.1
listen-address=127.0.0.1

sbx

# /private/etc/resolver
nameserver 127.0.0.1
domain sbx
search_order 2

setdns.sh

#!/bin/bash

# Add the localhost dnsmasq server to the head of the nameserver list, if it
# is running

# short-circuits
if [ ! -f /etc/resolv.conf ]; then exit; fi

DNSMASQ_RUNNING=`ps auxw | grep [d]nsmasq`
if [ -z "$DNSMASQ_RUNNING" ]; then
    exit
fi

NAMESERVERS=$(cat /etc/resolv.conf  | grep ^nameserver | cut -d' ' -f2- | xargs echo -n)

if echo $NAMESERVERS | /usr/bin/egrep -q '127\.0\.0\.1' ; then
    exit
fi

logger -s setdns: adding 127.0.0.1 before existing list of nameservers $NAMESERVERS

# Find the device ID for the priamry internet interface
PSID=$( (scutil | grep PrimaryService | sed -e 's/.*PrimaryService : //')<< EOF
open
get State:/Network/Global/IPv4
d.show
quit
EOF
)

scutil << EOF
open
d.init
d.add ServerAddresses * 127.0.0.1 $NAMESERVERS
set State:/Network/Service/$PSID/DNS
quit
EOF