Here is how I made a walk-in movie theater for a community movie night.

Basic steps:

Get equipment
Get permission
Set-up
Show the movie

Note: A problem with this instructablewise is that the actual event takes place in the dark. I did not think to bring a good camera so the photos of the event are poor. Some photos are staged in my kitchen or backyard, I got tired of this pretty quick, so some things just don't have photos)

Step 1: Equipment

A lot of this project was just getting appropriate equipment. I bought most of the stuff from Amazon.com (links below). My intention was to get equipment that wasn't to crappy or too expensive. Also, I wanted to be able to re-use everything for other purposes.

Projector:
Epson EX3212 Projector

Speakers:
ION Block Rocker Bluetooth Portable Speaker

Audio Cables:
Belkin Y Adapter
25-Feet Gold Plated 3.5mm Male to 3.5mm Male Stereo Audio Cable

Power Inverter: (optional)
12 Pure Sine Power Inverter 600 Watt

Audio Amplifier: (optional)
Mini Amplifier

FM Transmitter: (optional)
Broadcast Home FM Transmitter

DVD Player:

Extension Cords:

*****************
Screen (big white tarp):
Sigman 18' x 24' White Tarp Heavy Duty
From MyTarp.com

Step 2: Equipment: Projector

After a lot of reading about them, I bought the best projector I could afford (<$300). This was refurbished. It is excellent.
You can see all the specs here: Epson EX3212 Projector

It uses 3 LCD screens -- the light is split with a prism and each color (red, green, blue) goes through its own screen. This looks better than DLP projects that have one LCD screen and then use filters to rapidly project one color at a time.

For the DVD player, I just used the one I had and connected with RCA cables. Only the video line (yellow) has to go from the DVD player to the projector. The audio (white/red) goes to the speakers.

**Updated: There are some other very awesome new projectors, if you are willing to spend a little more. These have HDMI capability, if that is your thing.

This one is expensive, but is wireless: Epson PowerLite 1761W 3LCD Projector

This one is under $400 and has 3D capability: Optoma W311 Full 3D

Step 3: Equipment: Audio

Speakers:
ION Block Rocker Bluetooth Portable Speaker

Audio Cables:
Belkin Y Adapter
25-Feet Gold Plated 3.5mm Male to 3.5mm Male Stereo Audio Cable

Audio Amplifier: (optional)
Mini Amplifier

FM Transmitter: (optional - did not use)
Broadcast Home FM Transmitter

Also -
A large bass amp
50 Watts PA Horn Speaker (used with min amplifier)

Step 4: Equipment: Screen / White Tarp

*****************
Screen (big white tarp):
Sigman 18' x 24' White Tarp Heavy Duty
From MyTarp.com

Step 5: Location

I scouted out a few locations and got it down to the parking lot next to the high-school gym. Or a public baseball field. I wanted people to be able to sit on the ground (not in there cars like a drive-in). So the backstop at the baseball field.

Step 6: Permission: to Show a Movie in Public

For most movies you have to get a non-theatrical public performance license to show a movie in a public park like this. Schools and libraries can buy a blanket permit that covers many movies for one year.

I used this company http://www.criterionpicusa.com/ I couldn't find a way to do everything online. But it was pretty easy.

Look at their online catalog for a movie they carry
Call the phone number
Talk to Eric
They pretty much just wanted to know if I was going to charge admission
They also needed the location, date, and approximate attendance
Get an invoice
Pay the invoice

I paid $275 for a one day license. I bought a fresh DVD from amazon for 5$.

If you want, they will ship you a DVD (or whatever format you want) for the cost of shipping. This way you can get movies after they have been in theaters, but before they are available for home.

Step 7: Permission: From the Town to Use the Location

I was not sure (and I am still not sure) what, or if there are, any laws about showing a movie outside (other than copyright). The only sign posted at the park was No Dogs Allowed.

Because I did not want to be arrested for showing a movie, I called the town hall and sent a detailed email. They had me come to a Board of Selectman Meeting to get a special permit. I just had to explain what I wanted to do, they asked a few simple questions, and that was it. The next day they dropped the permit off at my house (it is a small town, they did not all come.)

Step 8: Setup: Screen

Hoisten the mizin mast!!

We hung the screen from a bar that we hoisted up the side of a backstop.

To make the Bar:

Go to Home Depot
Find the section with chainlink fence
Buy 3 of the top pipes, they are 10'6" long and cost about 11$ each
Bring all that home
Connect the pipes, they fit together on there own
Drill a hole through each junction
Put eye bolts through the holes
Mark the pipes so you will be able to reassemble them in the same order

To raise the Bar:

Throw 4 ropes over the backstop
Re-assemeble the pipe
Tie the eye bolts to the ropes
Pull the ropes so the bar is a few feet of the ground

To raise the Tarp:

Cut 20 peices of string to a lenght 2Xs your forearm (about 2 feet)
Lay out the tarp in front of the bar
Tie the tarp to the bar
Tie the knots like your shoes
Pull the ropes until the tarp is up (like a movie screen)
Tie off the ropes

Step 9: Setup: Projector

The trick to setting up the projector was to get it the right distance from the screen for a big picture. A problem we had was that the sun was setting so the screen was brightly lit. We could not really tell if the projector was even turned on until the sun went down.

We were able to run 150' of extension cord from the "Snack Shack".

The project was about 30' from the screen ( on the 3rd base line).

Here is a tool to figure it out ahead of time: http://www.epson.com/alf_upload/landing/distance-calculator/

Step 10: Setup: Audio

For now, go look at this - https://www.instructables.com/id/Connect-two-block-rockers-with-wires/

Step 11: Results

Show the movie once it is dark.

This photo is taken from deep right field, the image is about 18' tall.

Step 12: Follow Up

Step 13: Better Tarp

This is a 12x20 foot tarp with a black out material applied to one side. It is sold specifically for outdoor movies. It totally blocks light behind the screen, and the projection is not visible from behind the screen. It is a little shiny, but I bet it will dull a little.

It should probably be mounted in a giant frame.