A collection of Old Time Radio plays in M4B audiobook files for your iPod... Low quality / high compression:

Abbott and Costello - Who's on First
Black Museum - Four Small Bottles
CBS Radio Mystery Theater - A Study in Scarlet
CBS Radio Mystery Theater - The Man In Black
Dimension X - The Knock
Dragnet - Big Partner
Dragnet - Big Smart Guy
Dragnet - The Big Odd
Green Hornet - Political Racket
Green Hornet - Reservoir For Murder
Green Hornet - Smuggler Signs His Name
Green Hornet - The Letter 1
Green Hornet - Torpedo on Wheels
Orson Welles - War of the Worlds
Weird Circle - Dr Jeckyl and Mr Hyde

Chances are, these files won't play easily in your MP3 player (Winamp), unless you rename them from *.M4B to *.M4A.  Media Player Classic, VLC, and other video players should have no problem as they are...