While investigating the story behind the photo of a Mac-using David Simon that I posted on the blog last week, I e-mailed Greg Spence, the man responsible for the post-production of Simon’s next project, an HBO mini-series called “Generation Kill.”

Rather than discuss what one would expect – his possible use of high-end Macs equipped with Final Cut Pro and other high-end Apple video tools – Spence instead described how he and his colleagues depend on Apple’s consumer products.

In particular Spence said iChat is an integral part of his daily work, serving in multiple capacities.

“We use iChat religiously in our cutting rooms, as do most sound and picture editors and assistants,” Spence wrote in his e-mail. “Sometimes it is as short-range as a person in an intense screening or editorial meeting sending messages to someone just outside the door, or it can be as distant as across the globe.”

But I was surprised to learn that iChat is more than just a great communicator; it also can play a role in the production process, at least on some projects.

“On lower budget pictures we use iChat to record ADR [additional dialogue recording] from actors around the world,” Spence said.

“We sign on iChat, set up cameras, the director talks to the talent, they record the line... after each line the recordist simply drops it into the iChat window and we pull it down in Los Angeles. Lots of low-budget shows do this now and save up to $1,200 per hour. It isn’t super fast, but for a few lines it works great.”

Yet Spence has another use for iChat he considers the more vital than any other. In the middle of a five-month stay in London to work on the “Generation Kill” project, he is 5,500 miles away from his family in Santa Monica, Calif.

“I have regularly scheduled iSight conferences with my kids,” Spence said. His wife sets up her laptop at the breakfast table in Santa Monica, which coincides with his “tea time” in London.

“It makes all the difference in the world,” he said.