1) Never delete anything that you've already written! Just go back and
2) Create a new document called "NaNo 2012 Dump." After you're done writing for the day, copy and paste what you've written into the Dump document. I do this because my outline and my draft are two different documents, but I often write a more detailed outline of the chapter before I write the actual chapter, and I want my effort to count. This helps me track it more accurately.
I suspect that you Wrimos might have higher word counts than you've been reporting (not that you haven't been doing a stellar job thus far!)
Now for the standard stuff.
1) Word count today?
2) Word count total?
3) Would you like to live in the place where your book is set?
That's all, folks! Back to work!