Hourglass by Indigo Ray

Cool idea. And since you asked for comments and suggestions, here are a couple, some of which are a bit complex. Let's start with the simpler ones:

- The sand at the bottom would pile up in a pile that is higher in the center. ^

- The sand would also spread out and thin out slightly in the air as it falls down.

Getting a bit more complex:

- You could also build the wooden parts that are at the bottom and top and two (or more) poles to hold them together. They are all lathed objects.

And then a whole lot more complex:

- You could make the glass have thickness, in other words two slightly offset versions of the same profile one inside the other.

- And for maximum effect you could refract the background image through the glass... (You can rip that effect from my Halloween Party Drink filter).

All depends on how far you want to go with it.

That's why I figured I'd break it down to three levels of difficulty, so that you can choose where to end off...

But remember that you can always flip the hourglass with one Profile Gradient and Offset, so as to gain more time.