Animation.. Flash or Illustrator?

Can anyone give me a link or quick steps on how to build this effect of a continuos line.

http://www.aurora-design.co.uk/

Animation.. Flash or Illustrator?bmw

this will be a little tedious.

1) you need a vector image.

2) you break part the vector (Modify/Brake apart)

3)select like 300 frames and press F5 to create a key frame with the vector in it

4) then press F6 (this will create 300 individual keyframes)

5) now you are going to delete 99% of the image go to next frame and delete 98% of the image and so on.......

(the aurora animation has 45 frames till it is fully seen)