If I was going to add an Internal Speaker to my Zune HD, where could I find a speaker that would fit (what does the iPod touch use?) and if I do eventually add one, how could I allow it to play through the speakers only when no headphones are inserted?

Just Curious!

If you were to include a speaker inside your zune you would have to make room inside the case (there isn't room to do this) to put in a speaker and a circuit board that would auto change output. That being said the speaker for the iPod touch is paper thin might work but I highly doubt it. if you can find a broken iPod Touch you might be able to rig it up tho no guarantees Good luck tho tell us how things turn out

I'm thinking about having a buddy of mine cut a piece of metal similar to the zunes rear alluminum cover but I would need it a bit taller... I'm still messing with the idea, I really don't even need an internal speaker... If I ever do get around to doing this, it will be about a good 6 months from now after I finish my current projects

Yes if you make your own backing you should be able to make plenty of room. you could easily use a psp's speaker inside as those are smaller then tiny

Is there anywhere I can buy a board that changes output, or will I have to rig one up myself