danny@huuep:~$ ffmpeg -f alsa -ac 2 -i pulse -f x11grab -r 30 -s 1440x900 -i :0.0 -acodec pcm_s16le -vcodec libx264 -vpre lossless_ultrafast -threads 0 -y /home/danny/video.mkv
FFmpeg version SVN-r25838, Copyright (c) 2000-2010 the FFmpeg developers
  built on Jan 21 2011 09:10:31 with gcc 4.4.5
  configuration: --enable-libdc1394 --prefix=/usr --extra-cflags='-Wall -g ' --cc='ccache cc' --enable-shared --enable-libmp3lame --enable-gpl --enable-libvorbis --enable-pthreads --enable-libfaac --enable-libxvid --enable-postproc --enable-x11grab --enable-libgsm --enable-libtheora --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libx264 --enable-libspeex --enable-nonfree --disable-stripping --enable-avfilter --enable-libdirac --disable-decoder=libdirac --enable-libschroedinger --disable-encoder=libschroedinger --enable-version3 --enable-libopenjpeg --enable-libvpx --enable-librtmp --extra-libs=-lgcrypt --disable-altivec --disable-armv5te --disable-armv6 --disable-vis
  libavutil     50.33. 0 / 50.33. 0
  libavcore      0.14. 0 /  0.14. 0
  libavcodec    52.97. 2 / 52.97. 2
  libavformat   52.87. 1 / 52.87. 1
  libavdevice   52. 2. 2 / 52. 2. 2
  libavfilter    1.65. 0 /  1.65. 0
  libswscale     0.12. 0 /  0.12. 0
  libpostproc   51. 2. 0 / 51. 2. 0
ALSA lib pcm.c:2190:(snd_pcm_open_noupdate) Unknown PCM pulse
[alsa @ 0x8184ca0] cannot open audio device pulse (No such file or directory)
pulse: Input/output error