What is the most amazing invention of the century?

My husband answers that often-asked question with this joke:

When a fellow was asked to name the most amazing invention, he surprised others by answering: "The thermos."

"What's so amazing about a thermos?" he was asked.

"Well, if you put hot stuff in it, it stays hot. If you put cold stuff in it, it stays cold," he said.

"What's so amazing about that?" asked his companion.

"Well, how does it know?" the man said.

The way Dave tells the joke always makes me laugh, even though I heard him tell it before.

But answering that question seriously, I would have to give the nod to the Internet as the most amazing invention.

When my daughters were young, I remember trying to afford a set of encyclopedias to help them with their school research. When we learned how expensive they were to buy, we decided we would rather drive our daughters to the library when they needed to do research.

Now, thanks to the Internet, no one has to leave home to have a literal world of information at his or her fingertips – and it's far better than any encyclopedia could offer.

Before I buy anything, I pull up reviews on the Internet, trying to read as many professional and customer reviews as possible. The Internet lets us all be well-informed consumers.

When I wanted to buy a new digital camera with a long telephoto lens, I typed that request into Google and soon had the top rated models to compare.

When we are planning a vacation to a new area, we pull up all the information we need on the Internet. It tells us what recreation is available in the area, offers directions to get there, lets us compare rates at various motels, informs us about points of interest we might miss, and offers restaurant reviews and menus. Sometimes the Internet also offers discount coupons or better hotel rates than we would get if we telephoned or stopped in.

If someone mentions a name or place with which I am not familiar, I "Google it," quickly learning all I need to know.

While I am now used to being able to research any topic in which I have interest, I must admit I am surprised when the Internet can supply answers to questions I can't quite put into words.

For instance, I typed in "racing pulse rate," not sure what medical facts I needed to learn about that condition. In split seconds, the Internet offered articles on the leading causes of racing pulse rate.

Some say there is a down side to looking for medical knowledge on the Internet. "You can really scare yourself unnecessarily when you read about symptoms and imagine that you have a serious disease," said one friend.

I counter that by saying the Internet just gives you enough information so you know what questions to ask your doctor. I get much more out of my doctor's visits when I have enough knowledge ahead of time to know what questions to ask.

But I do admit one has to be careful of what Internet source is offering information. Is it a commercial site with something to sell? Or, is it a respected medical site such as Johns Hopkins University?

The Internet is changing the way we do business along with how we buy things.

I just helped my daughter buy a car in Colorado while we both were in Florida during her recent vacation.

Before she came to Florida, she researched the cars she was interested in, going to Consumer Reports to learn the pros and cons of models. Then she went to dealerships to drive them.

What she learned, along with narrowing down her choice of a car, is that she should never step into a dealership alone. "It makes me sick in the stomach and I never know how to get away from them," she said.

I told her she could use the Internet to negotiate with several dealers at a time, all without leaving my home.

She was upfront with the car dealers, telling them she was going to buy a car within a week but letting them know she was comparing prices from all dealers in her area.

To get that information, a prospective buyer has to give a telephone number. That meant Maria's phone never stopped ringing during her week's vacation. Even when we were out on our boat, she was getting calls from dealers.

But it all paid off when we could compare "apples with apples," receiving in emails what the car included then selecting the dealer with the best price.

Then I took over, telling that dealer we wanted "out the door pricing." In the past, I had learned the hard way if you don't get out the door pricing in writing, when it comes time to sign on the bottom line, you end up paying more than you thought.

My favorite words when negotiating: "I'm sorry, we just can't do that." Repeat over and over.

"But that's the best deal we were offered," Maria said. "You're going to lose the deal for me."

She was amazed when the dealer met our price. Then she used the Internet to post an ad to sell her old car. She had five offers the first day.

Even when we think we know the power of the Internet, we keep getting surprised at how fast it gets things done. It's definitely my idea of the most life-changing invention.

What's yours?