Present.me is new (beta) wonderful site for uploading powerpoint presentations then adding a narration. The finished product actually combines the two so you see the presentation and the narrator as well. When the presentation is done you can share it w/ others via a URL or embed into a site. If you upgrade your account you can then activate privacy options and others as well.
I highly recommend checking out Present.me by clicking here!!
Thanks to Richard Byrne's excellent blog for the tip.