This is my first attempt on the tweetcoding contest held by grant skinner... and I do have to say thats its very funny indeed :)

Note that this example does not fully use object 'o' for persistant data, yet. And to save place I also had to shortcut Math.cos (but hey, evertyhing is till in the 140 char span, sorry 139 chars) 

if(!i)o.h=50+r()*50,g.clear(),v=.2,c=m.cos;//43 chars
ls(1,0,.4+c(i*v)*.6);//21 chars
(!i?mt:lt)(m.sin(i*v)*(i*v*.2),c(i*v)*o.h-i*.1+o.h);//52 chars
(i>o.h*.2*100)?i=0:i++;//23 chars
Compiled entry here.

More about the competition here.

If time allow, its possible that I will attempt to do a few variations before the final submit.