Whither Writing Tools?

There's been whole books on the pencil and other writing implements.  So how about one on something that makes revision easier — the lowly eraser?  The too-often maligned spellchecker (which spelling-challenge me loves, loves, loves)? That came to mind when reading this from Brian Hayes on Electrifying Language.

The eraser had a particularly bad reputation, under the thesis that "if the technology makes error correction easy, students will make more errors." I have to add that my own view of the computer as a writing instrument has always been that it's not so much a better pencil as a better eraser, allowing me to fix my mistakes and change my mind incessantly, without ever rubbing a hole in the page. The first time I held down the delete key on an early IBM PC and watched whole sentences and paragraphs disappear, one character at a time, as if sucked through a straw—that was a vision of a better future for writers.