Motion on Raspberry Pi

1. Install motion package

sudo apt-get install motion

2. Install ffmpeg package

sudo apt-get install ffmpeg

3. Edit motion.conf

sudo nano /etc/motion/motion.conf

   Modify the settings as below  
   - daemon off
   - webcam_localhost off
   - width 320
   - height 240
   - framerate 15

4. Launch motion

sudo motion

5. Browse the video stream (Firefox)
   Type http://x.x.x.x:8081 

Hardware:
   Raspberry PiPS3 Eye
   EW-77811Uh WiFi dongle

Summary...
   CPU usage(top) was around 85% when motion was detected.
   The latency was not good, about 1s delay. 
   Tuning the parameter might help but guessing gstreamer is better... 

Reference:
   http://www.raspberrypi.org/phpBB3/viewtopic.php?f=26&t=7397