Here are the sound files available for your listening pleasure (all files are in au. format):

Negative Creep 140k.
School 120k.
Big Cheese354k.
Smells Like Teen Spirit 378k.
Lithium362k.
Endless, Nameless - you know, that hidden song
on "Nevermind" - 168k.
Sliver 125k.
Aneurysm 162k.
Heart-Shaped Box372k.
Rape Me 356k.
Pennyroyal Tea338k.
About a Girl from "Unplugged" - 215k.
Lake of Fire 150k.
Even in His Youth 161k.
Curmudgeon 162k.
D7 219k.