OK, trivia time: What is the fastest-adopted consumer electronic gadget of all time? The answer is the boom box.

That's the finding of Cal Poly Pomona marketing professor Tarique Hossain, who measured the household penetration of sundry products, from fax machines to camcorders, over their first seven years.

The boom box had an "observed penetration rate" of 63 percent seven years after its 1975 invention. The CD player came in at 56 percent and the DVD player at 50 percent. Tied for last among the 20 products studied: the PC TV and the color TV at 1 percent penetration.

But -- you knew there was going to be a "but," right? -- in our rapidly evolving technological world, the boom box's reign might be threatened. Or not.

Four years ago this month, Apple released the first iPad, so tablets still have a shot. But it's unlikely, says consumer electronics expert Don Lindich. "Tablets are great but they still have limitations compared to a PC [no USB on an iPad, for example]," he said. "If they ever make a $299 iPad I think adoption will skyrocket as it is the product people want."

As for the boom box: "I think there was a 'hip and cool' factor to it back in the 1970s," Lindich said, "and it served multiple needs. It could serve as a main music system in a bedroom ... and could be taken to different rooms in the house, to the beach or a park. And it combined a lot of functionality in a single box, namely a cassette or eight-track player, tuner and speakers."