Flash to Epic Word Count

The boundaries fluctuate, and everyone can find an example that violates these word ranges; however, in general:

1-500. Flash Fiction
501 - 2,000. Short Shorts
2001 - 20,000. Short Stories
20,001 - 50,000. Novella
50,001 - 100,000. Novel (If you're a first-time novelist, best to be between 60-90K.)
over 100K. Big novel (significant investment by the publisher)
150K+. Epic Novel (Think "Lord of the Rings", "Gone With The Wind")

I've gleaned this from the number of times this question has come up, various articles and conferences, and those self-help books that all writer's love. :-)