Alternative to Hanging Drop Crystallization Forgive my ignorance if I am way off, but I was having a look at the crystallization of a number of different substances (e.g. proteins) through the hanging drop vapour diffusion method.

The examples given use a precipitating agent (e.g. $10~\%\ \ce{NaCl}$) at the bottom of the well and then you put the liquid protein you are looking at upside down on the top cover and the water moves from the protein into the precipitating agent, slowly crystallizing the protein.

So my question is, for simplicity would it be possible to use a divided container (e.g. petri dish) which has two compartments that share the same atmosphere to achieve the same thing, that is have a container that has a salt solution on one side, and the solution I wish to crystallize on the other?

Would this likely work?
The process you are describing is essentially the sitting drop crystallisation.

Yes, it is used. Frequently, sitting drop is used in robotic setups, because robots have a much harder time creating hanging drops. With a sitting drop, it becomes simple; just pipet a drop into the sitting drop reservoir.

Gerhard mentioned that the hanging drop method is the preferred one for manual handling since it becomes easier to handle the crystals. Possibly because they sit at the bottom of the hanging drop rather than stick to the ground of a sitting drop’s reservoir.