iirc this streams the contents of an x11 window via flash...

screenfire

#!/bin/ksh
res=svga

eval $(xwininfo -frame | awk '/Absolute upper-left X/ { print "x="$NF }
                       /Absolute upper-left Y/ { print "y="$NF }
                       /Width/ { print "width="$NF }
                       /Height/ { print "height="$NF }')

offset=${x},${y}
res=$(( (width/16)*16))x$(( (height/16)*16))

ffservercfg=$(mktemp /tmp/screenfire.XXXXXXXXXX) || exit 1
cat >$ffservercfg <<EOT
Port 8090
BindAddress 0.0.0.0
MaxClients 1000
MaxBandwidth 1000
CustomLog -

<Feed screenfire.ffm>
   File /home/stef/data/screenfire.ffm
   FileMaxSize 32M
   ACL allow 127.0.0.1
</Feed>

<Stream screenfire.avi>
   Feed screenfire.ffm
   Format avi
   VideoBitRate 600
   VideoFrameRate 25
   VideoSize ${res}
   VideoGopSize 12
   VideoHighQuality
   Video4MotionVector
   NoAudio
</Stream>

<Stream stat.html>
   Format status
   ACL allow localhost
   ACL allow 192.168.2.0 192.168.2.255
</Stream>

<Redirect index.html>
   URL http://localhost:8090/screenfire.avi
</Redirect>
EOT

cat $ffservercfg

ffserver -f $ffservercfg &
sleep 1
ffmpeg -f x11grab -s ${res} -r 25 -i $DISPLAY+${offset} http://localhost:8090/screenfire.ffm || { 
   kill %1
   rm $ffservercfg
}