[ScottBooks]

I was under the impression that if I wanted to re-download a previously deleted book, I could just go back into the Kindle store, or go to the Kindle site from my computer, and simply hit "buy" again. I figured I just wouldn't be charged when it was re-sent.

Actually you will be using the Content Manager to perform this funtion. (In Whispernetland).
On the computer you'd do it on the "Manage my Kindle" page.

Not sure what would happen if you tried to repurchase something you already own. There are warnings on the page if you've already bought the item...hmmm...anyone want to experiment with a Nuclear Science book?