For instance, could you calculate the appropriate price to pay if you were buying Britney Spears's future earnings today?

Yes, as long as you're willing to make assumptions about what her future earnings payment stream will look like.

What about a rock; does it have an NPV of zero?

Generally, present values are calculated for things that have a stream of payments, or even a single lump sum payment, some time in the future. Unless the rock is farting diamonds, there's nothing to calculate.

Would either of you mind if I emailed you with various general sorts of things?

I'd be flattered Scrappy!

No, seriously. They tell accountant jokes.

The "classic" one is the self-deprecating, "An actuary is someone who didn't have the personality to be an accountant."

The "classic" one is the self-deprecating, "An actuary is someone who didn't have the personality to be an accountant."

I thought accountants told that one....

Shouldn't that be reversed?

Depends. How do you feel about accountants? Also, do you run Mac OS?

Unless the rock is farting diamonds, there's nothing to calculate.

You know, I'd buy that rock for the comedy value alone.

My mac is more fun than an accountant, my linux box weirder, and my windoze box crankier. All three with personality, hence my realization that I'd read the punchline reversed in my head, and the deleting.

(Curse you and your quick ctrl-c! Curse you!!!!)

Glances up at Accounting Degree hanging on office wall. Reminds self that said degree never was used. Resumes personality having behavior.

Two theatre degrees here. Not so much on the accounting.

Though I can make sense of a fast fourier transfer display.

Glances up at Actuarial Science Degree hanging on office wall. Reminds self that said degree never was used. Resumes personality having behavior.