There are two prices on the site $45 + GST here:
http://au.element14.com/raspberry-pi/raspberry-pi-cam/kit-ra…
and $55 + GST here
http://au.element14.com/raspberry-pi/raspberry-pi-cam/kit-ra…
Search the web - there's come stuff on motion detection and computer vision with opencv and simplecv. Worth it just to play around.
This is the A board so its got less memory, no ethernet and 1 USB compared to the B board. But the idea is its lower powered so you can power it from a USB battery pack. And just use a USB hub and ethernet adaptor to set it up.
This is what inspired me http://www.raspberrypi.org/archives/4799 time lapse in a coffee can !!
Just to clarify, only the A board on it's own can be USB powered. If you connect the camera module, it requires an additional 250mA, bringing the total power draw from an A spec board up to ~750mA. USB spec defines maximum power draw of 500mA.