I want to record my own voice into Fallout, as well as splice existing voices to say situation appropriate things.

I was wondering, can the G.E.C.K. generate lip synch files?

Fallout 3 uses Ogg Vorbis sound files? I was wondering what is the exact format parameters of the Ogg Vorbis?
In oblivion for example; I had to use Mono 64Kbps 44.1Khz MP3 files for the finished sound.

I wanted to redirect to a new sound, how is that done?

Not sure exactly if this is what you want, and I can't vouch for it as I never have used the tutorial myself, but it was mentioned about a page back and is made by one of our forum frequenters.

http://fallout3nexus.com/downloads/file.php?id=11802

Hopefully that can help you out.

My tutorial on Audio Holotapes may be of interest, link is in my sig.

In my case I'm teaching how to create audio holotapes, but it covers the voice/sound files and links to the lip-sync stuffs.

Luck,

Miax