I ordered an upside down hanging tomato planter from Gardener's Supply. It arrived on Saturday and I spent an hour or so assembling the planter, potting an eggplant transplant, and mounting it on a spare Shephard's Hook we happened to have in the garage.
The Shephard's Hook will likely be a temporary home for several reasons. Filled with potting soil, the basket is heavier than it looks. After the eggplant grows for a few weeks it will not be long before the leaves begin to touch the ground. The Shephard's Hook is not "heavy duty" and likely would not support the full weight of a fully grown eggplant.
If you look closely, you'll notice the twine I am using to anchor the planter so it doesn't collapse under its' own weight. That particular hook is designed for a bird feeder and three gallons of potting soil weighs considerable more than a quart of bird seed.
If I can manage to keep the eggplant alive and prospering for a few weeks I'll find a better place to hang it, but for now I'd rather not invest any more time, effort, or money in the planter.
I'll post picture updates periodically so you can see the eggplant's progress.