Suppose, for example, that your 30-gigabyte iPod with video has some problems. If the device is still under warranty, you send it back to Apple. If the warranty has lapsed, you can still send it to Apple and it will cost $129 to repair or $59 for a new battery, which is often the problem.

At Rapid Repair, the highest repair cost would $90, but often runs less if the trouble is minor. The company also offers to replace batteries for $20.

“About half our customers buy the parts and do their repairs themselves,” Mr. Vronko said. He suggests, though, that once the item is about five years old, it’s probably not worth fixing.

What if the product is still under warranty, but something that isn’t covered breaks, and you want to get someone to fix it for less than the manufacturer will charge? You need to check if the repair company is authorized by the manufacturer. If it is, then typically the repair can be done and the warranty remains valid if other problems crop up.

Here is another option. Let’s say you have a technologically savvy friend who is willing to help you figure out your computer’s problem. But she lives in California and you live in London.

There are a variety of services and software that allow you to remotely control a computer. I checked out a company called CrossLoop, which offers two options. You can download software from the company’s Web site that allows you to remotely gain access to another computer system  either MacIntosh or Microsoft Windows  and diagnose the difficulty.

To protect security, said Mrinal Desai, co-founder of CrossLoop, each time you and your friend use the software, you must type in a randomly generated 12-digit code that is changed for each use. And both of you have to do it within two minutes.