make /tmp writeable for compilation:
-- mount -o defaults,remount,rw /tmp;

libvorbis - source
-- wget http://downloads.xiph.org/releases/vorbis/libvorbis-1.1.2.tar.gz;
-- tar -xzvf libvorbis-1.1.2.tar.gz;
-- cd libvorbis-1.1.2;
-- ./configure --prefix=/usr && make;
-- make install;
-- cd ../;
-- rm -rf libvorbis*;

LAME
-- wget http://superb-west.dl.sourceforge.net/sourceforge/lame/lame-3.97.tar.gz;
-- tar -xzvf lame-3.97.tar.gz;
-- cd lame-3.97;
-- ./configure --enable-shared --prefix=/usr;
-- make;
-- make install;
-- cd ..;
-- rm -rf lame*;

ffmpeg
-- wget http://ffmpeg.mplayerhq.hu/ffmpeg-export-snapshot.tar.bz2;
-- tar -xjvf ffmpeg-export-snapshot.tar.bz2;
-- cd ffmpeg-export-XXXXXXX;
-- ./configure --enable-libmp3lame --enable-libvorbis --enable-shared --prefix=/usr;
-- make clean && make;
-- make install;
-- mkdir /usr/local/include/ffmpeg;
-- cp libavformat/avio.h /usr/local/include/ffmpeg;
-- cp libavformat/avformat.h /usr/local/include/ffmpeg;
-- cp libavcodec/avcodec.h /usr/local/include/ffmpeg;
-- cd ..;
-- rm -rf ffmpeg*;

Ruby
-- wget ftp://ftp.ruby-lang.org/pub/ruby/1.8/ruby-1.8.6.tar.gz;
-- tar -xzvf ruby-1.8.6.tar.gz;
-- cd ruby-1.8.6;
-- ./configure; make; make install;
-- cd ..;
-- rm -rf ruby*;

FLVTool2
-- wget http://rubyforge.org/frs/download.php/17497/flvtool2-1.0.6.tgz;
-- tar -xzvf flvtool2-1.0.6.tgz;
-- cd flvtool2-1.0.6;
-- ruby setup.rb config;
-- ruby setup.rb setup;
-- ruby setup.rb install;
-- cd ..;
-- rm -rf flvtool2*;

ffmpeg-php
-- wget http://internap.dl.sourceforge.net/sourceforge/ffmpeg-php/ffmpeg-php-0.5.0.tbz2;
-- tar -xjvf ffmpeg-php-0.5.0.tbz2;
-- cd ffmpeg-php-0.5.0;
-- phpize;
-- ./configure && make;
-- make install;
-- cd ..;
-- rm -rf ffmpeg*;
-- save the extension dir outputted to the screen for later.

MPlayer/MEncoder

-- wget http://www4.mplayerhq.hu/MPlayer/releases/MPlayer-1.0rc2.tar.bz2;
-- tar -xjvf MPlayer-1.0rc2.tar.bz2;
-- cd MPlayer-1.0rc2;
-- ./configure && make; make install;
-- cd ..;
-- rm -rf MPlayer*;

Change /tmp back to unwriteable to undo above change to /tmp
-- mount -o defaults,remount /tmp;

-- edit global php.ini
-- change extension_dir to what we saved from the ffmpeg-php compile earlier.
-- under 'Dynamic Extensions', add the following line:
extension = ffmpeg.so