illuminati,
Check this out. This is probably close to what you want to do.
http://hackedgadgets.com/2010/06/21/diy-am-transmitter-from-a-555-timer-or-picaxe-microcontroller/
Pretty much the MC is used to generate an AM carrier signal but some more external components are needed to modify the carrier so it can generate sound. AM is a very simple for of transmission and can be done with a few external components.
I'm a radio operator so i <3 this kind of stuff.