I was answering KB, and got carried away. Here's what I'd recommend.
If I had my way, the 12 closest churches would all get together, rent the local football field, and have a potluck. This potluck happen at 7:00 AM some Sunday morning in July, and it would be a black tie affair. Everyone would bring cold delicacies worthy of a King. There would be bread and wine in the style and manner of each church on every table in wrappers saying, "Please open when asked." The placemats would have printed on them the doxology and Thou Art Worthy
Each church would bring a flag on a 10 foot pole, a unique flag that would represent their church. Each church's tables would have miniature versions of this same flag on them. Each placemat would also have a sticker on it showing another church's flag. (They would be in triplets. The placemats at Church A's table would have three stickers for church B in a row, then three stickers for church C, then 3 for D etc.)
The food would be placed on the tables, and everyone would follow their flag to a place just behind the their end zone. 6 churches would be circled around 6 flags in the south end, and 6 in the north end. Each church would be advised to place seats behind the end zone for those who were not able to stand for 90 minutes.
An MC with tophat and tails would run to the center of the field precisely at 7:00 announcing that we were here to worship our King. He would then pull a name out of the hat, and call that church to the tables in the center. They would let out a practiced cheer then walk to the center of the field while singing a chorus - into which everyone could join. A representative of that church would then stand to the mic, and deliver a 2 minute prayer of praise and allegiance to the King. Then the MC would call the next church forward.
That process would take an hour and a half.
After the last church had entered, someone with a strong and steady voice of pleasant range would lead everyone in "Thou Art Worthy." followed by a praise of God for the riches on the table, and free everyone to begin eating.
A minister (chosen by lots well prior to the meeting day) would deliver a message on the meaning of the bread, and the unity of the body of Christ. 5 minutes tops. :-) At that point, he would free the assembled body partake of the bread together. Each church would observe their customary respects toward the elements in administering to their own people. Then a second minister would follow the same protocol with the drink.
At this point, the ministers would all sit down quietly, and enjoy the meal with everyone else.
When everyone had eaten, the flag bearer of each church would be asked to return to his place in the end zone, and everyone would be asked to rally around, not their own flag, but the flag that matched their placemat sticker.
With the people all nicely mixed together, a caller would lead everyone in a responsive recitation of Psalm 122 (probably in the Message translation). After the caller spoke each line, the assembled body would shout it back to him. When the Psalm was done, and when any spontaneous shouting died down, our singer would lead everyone in the doxology.
At that point, the flags would do one more turn around the field, and as your church's flag passed you, you would fall in line behind it and head for the parking lot.
It should be right around 10:00 AM by this point, and the sun should just be starting to get too warm for black tie outdoors. I would recommend there be a couple RV's in the parking lot for people to change out of dress clothes into work clothes, and it would be time to break down the tables and chairs.