Four years ago, Clark and his wife got what’s called a Replay TV. Lane, his wife, was not happy about another gadget in her home. But she couldn’t be happier now. She’s addicted to recording programs on this digital gadget. You tell it what to record and you watch it at your leisure. Some of them even have “commercial skip,” which automatically skips commercials. It’s getting huge. Tivo was the first company to come out with the gadget. But as more companies come out with them, Tivo has put its units on sale. The cheapest Tivo DVR is $100 with a rebate. The most expensive is about $400 right now. But the machine is not the costly item. It’s the monthly charge for the programming. It’s about $13 a month, or you can buy a lifetime use for $300. That’s a good bet if Tivo survives. If not, it’ll be a license that won’t be worth anything.