I am pretty sure people know about the .mozconfig file but....

[jmcd9336]

I noticed on the mozilla site you can specify the export statements in the 
.mozconfig 

but you need to do it twice once is just a plain "x=y" then with 
"mk_add_options x=y"
For example:

MOZILLA_OFFICIAL=1
mk_add_options MOZILLA_OFFICIAL=1

so once you have done your 

cvs co mozilla/client.mk


Don't copy this .mozconfig off here I haven't gotten it to build cleanly ... 
yet.... 

# Options for 'configure' (same as command-line options).
ac_add_options --with-pthreads
ac_add_options --with-system-jpeg=/usr/local
ac_add_options --with-system-zlib=/usr/local
ac_add_options --with-system-png=/usr/local
ac_add_options --with-system-mng=/usr
ac_add_options --enable-toolkit-gtk
ac_add_options --enable-toolkit-xlib
ac_add_options --enable-toolkit-qt
ac_add_options --with-qtdir=/usr/lib/qt3-gcc2.96
ac_add_options --enable-calendar
ac_add_options --enable-xft
ac_add_options --enable-crypto
ac_add_options --disable-jsd
ac_add_options --disable-tests
ac_add_options --disable-debug
ac_add_options --disable-dtd-debug
ac_add_options --disable-logging
ac_add_options --enable-reorder
ac_add_options --enable-strip
ac_add_options --enable-xterm-updates
ac_add_options --with-default-mozilla-five-home=/usr/local/mozilla
ac_add_options --enable-svg
mk_add_options MOZ_INTERNAL_LIBART_LGPL=1
MOZ_INTERNAL_LIBART_LGPL=1
MOZ_CALENDAR=1
mk_add_options MOZ_CALENDAR=1
MOZILLA_OFFICIAL=1
mk_add_options MOZILLA_OFFICIAL=1
mk_add_options BUILD_OFFICIAL=1
BUILD_OFFICIAL=1