BIRMINGHAM, Ala. — It's a wonder vacation Bible school made it out of the 1960s.

Back in the days of black-and-white TV, churches offered kids lemonade, cookies and flannel-board stories about Jesus, all set to a clanging piano. Children sat in short wooden chairs and listened to the tales for what seemed like an eternity.

Things are different in 2008. DVDs and video screens are everywhere, along with professionally recorded music, dancing and slick lesson books. Kids are as likely to jump on inflatable moon bounces or go to water parks as play on a church swingset once Bible time is done.

Vacation Bible school, once a homestyle tradition, has become big business, with families helping foot the bill through registration fees and donations. A handful of Christian publishers provide the curriculum, thereby setting the summertime agenda for millions of elementary-age kids at thousands of churches nationwide.

"Gone are the days of making birdhouses and golden macaroni frames," said Kevin Clark, the children's pastor at Life Church in suburban Birmingham for the last eight years. "It costs a lot more compared to what it did when I first came here, but it's really good."

At Mountain Brook Community Church, volunteer John Byrd pulls on a black wig, puts on a long white coat and gyrates at the front of the chapel in his role as a professor in this year's Power Lab VBS, a curriculum produced by Colorado-based Group Publishing Inc.

Jumping around with a keyboard slung around his neck, he lip-syncs a song about the power of Jesus — the most powerful thing there is, the lyrics say.

"What did we learn yesterday?" a leader calls out above the buzz of excited children.

"Jesus gives us the power to be thankful!" they yell back.

Used by hundreds of churches this year, the Power Lab theme incorporates music, DVDs, crafts and handouts. Children's pastor Walter Arroyo said the $2,000 investment is well worth it for the non-denominational church.

Small groups of children move between classrooms every few minutes rather than sit in one place, and all the activities and lessons tie in to a central daily idea. Arroyo supervises, patrolling the church campus with a walkie-talkie and clipboard.

"What it has helped us do is organize and keep things moving," said Arroyo. "We're committed to the message of the gospel, but we also have to engage them in their world."

For children's pastor Chuck McCammon, 38, VBS 2.0 is all about using new tools to reach children who have grown up on TVs and computers.

"The biggest difference between now and when I was a kid is we try to make it more interactive, with things that are more tactile," said McCammon. His church does its best to pull in children from a wide area. This year, Valleydale Baptist advertised VBS with a billboard on Interstate 65.

The roots of vacation Bible school go back at least 130 years, when Christian summer camps began operating.

A doctor's wife in New York City is widely credited with holding the first true vacation Bible school in 1898 in a rented beer hall.

Baptists began publishing vacation Bible school materials in 1922, and the format was mostly unchanged for decades, according to Mary Katharine Hunt of LifeWay Christian Resources, the Southern Baptist publishing arm.

But in the 1990s, LifeWay, the non-denominational Group Publishing and other companies began turning out expansive packages with everything from Bible-based curriculums to craft supplies and professionally produced music and videos.

Publishers won't release sales figures on their VBS products. But the Southern Baptist Convention said nearly 26,600 churches reported using LifeWay's VBS materials last year with a total enrollment of almost 2.9 million children.

Vacation Bible school is most popular in the Southeast, where it's seen as a way to bring new families into the church, but it's hardly a regional phenomenon.

"We have churches all over the country using our vacation Bible school material," Hunt said. "Obviously it's strongest in the Bible Belt, but we have tons of churches using our material in California. It's happening in New York."

Small churches generally spend no more than a few hundred dollars on VBS, she said, but some spend $2,000, or even more.

Many churches seek donations, charge registration fees or sell T-shirts to help cover the increased cost of materials plus camp-style extras like visits to water parks, said Jody Brolsma, senior vacation Bible school editor at Group Publishing in Loveland, Colo.

"Thirty dollars isn't unheard of for a day-camp-style experience, and some charge more," said Brolsma.

To help defray costs, many churches that purchase materials from companies like Group Publishing share as much as they can. Copyright laws prohibit copying most music and videos, but almost everything else is fair game.

"The main thing is to help churches, no matter how large they are, pull off a really spectacular event and reach families with the gospel," said Hunt. "The message hasn't changed, but the method has."