cross eyed stereo pair, here is a still: 
~3.3 meg 900 x600, 16 sec, divx:
http://webpages.charter.net/paprmh/imgs/3d_frontlight.avi
That is very very clever. Great idea, well executed. How did you get the bat to fly behind the trees?
The stereo pair isn’t quite right somehow… makes my brain hurt. I love it when people get into the Halloween spirit 
Thankyou for making this and sharing it! Good work 
COOOOOOOL!
Wow, I’m dizzy.
That’s really cool! Especially the “BOO” part. Make more 
yeah, the origional stereo pair is a bit off because I don’t have a stereo camera- I just used my digital cam and did what they call a cha-cha shot. Unfortuately this also means that the right and left frames are probably 10 sec apart so that any small breeze will move the leaves a bit and that causes the artifacts…
To get the bat to go behind the trees I just gimped a quick mask of the trees only and did an alpha over after the render. ( I love the sequece editor- one of blenders most overlooked features)
This was just a test to see if I could actually work in 3d and place blender objects in 3d space to match a 3d photo - 5 days from start to finish- Took the pics last sunday and tried to get it done for the animation challenge (of course it wouldn’t qualify because of the rules…but I just wanted to see if I could make a decent anim in the time frame allowed…)
BTW- pure blender except for the background photo editing in gimp