sh-4.0$ ffmpeg -f video4linux2 -s 320x240 -r 5 /dev/video0 -f m4v out.m4v
FFmpeg version 0.5, Copyright (c) 2000-2009 Fabrice Bellard, et al.
  configuration: --prefix=/usr --enable-gpl --enable-libmp3lame --enable-libvorbis --enable-libfaac --enable-libfaad --enable-libxvid --enable-libx264 --enable-libtheora --enable-postproc --enable-shared --enable-pthreads --enable-x11grab --enable-swscale
  libavutil     49.15. 0 / 49.15. 0
  libavcodec    52.20. 0 / 52.20. 0
  libavformat   52.31. 0 / 52.31. 0
  libavdevice   52. 1. 0 / 52. 1. 0
  libswscale     0. 7. 1 /  0. 7. 1
  libpostproc   51. 2. 0 / 51. 2. 0
  built on Apr 18 2009 20:24:32, gcc: 4.3.3
Unable to find a suitable output format for '/dev/video0'