BYU's free mp3 speech archive
I discovered an awesome site Wednesday night: Speeches.byu.edu.
They've made mp3's available of speeches given at BYU all the way back to 1949. (Here's one from 1950 by President George Albert Smith!)
You can browse the talks by speaker, topic, or year. Here's a 2001 talk by Elder Bednar before being ordained to the apostleship, and Here's Elder Holland's famous "Of Souls, Symbols, and Sacraments" talk from 1988.
You can also get them in HTML / PDF formats for free. I wish I would have known about this earlier. It's a great resource.