Not sure if this is obfuscated (actually I'm pretty sure it isn't) but here's one:

++$*;while(1){($_,$*)=($_+$*,$_);print;}
#By fatalserpent; code in Public Domain
[download]

I'm also a bit worried that it goes dry in less than a second... number generation justs stops..., it says it's reached infinity. Is this a problem with the code, or is my CPU just too fast?