What is the connection between Martha Stewart and home refinancings? Americans seem to be obsessed with both of them right now. They both have to do with home improvement. And experts keep predicting that both of them must have run their course in terms of growth and popularity, only to be surprised again and again at how much staying power they have.

Okay that's a cheap way to get the focus off the Martha soap opera and put it back on the economy, but if it's working so far - stick with me. Because the numbers we're seeing on mortgage refinancings are beyond eye-popping - they are historic in proportion.

The mortgage refi boom of the past few months has become a tidal wave. The Mortgage Bankers Association is reporting today that its index of refinancing jumped by nearly 13 percent last week to 9,978. Some perspective: that index used to average around 300 or 400. When it jumped above 1000, mortgage geeks were excited. Now it's nearly at 10,000! This is huge, for consumers and for the economy.

David Berson is the chief economist for Fannie Mae and just this week he raised his forecast for total mortgage market activity this year again as the refinancings just keep mounting. In January he thought total mortgage volume in 2003 would be $2.15 trillion. But by March he raised that forecast to $3.2 trillion, and now he has boosted that forecast to $3.7 trillion. His forecast for sales, or mortgages to purchase homes didn't change much: from $1.02 trillion to $1.08 trillion. It's almost all due to the refi picture: that forecast went from $1.06 trillion to $2.59 trillion!!!!!!!!

And that number he's forecasting for total refi's in 2003 is nearly as big as the entire mortgage market was in 2002! Wow.

As for how much this helps consumers, David Wyss of S&P put it this way. If you have a $125,000 mortgage and you refinance and drop your mortgage rate by a percentage point (the average 30-year fixed rate last week was 5.13% according to the MBA so it wouldn't be too hard for a lot of people), you save about a hundred bucks a month. That's a significant chunk of change for a lot of families.

According to Berson, right now about 45% of the refinancings being done right now are cash-out refi's where people whose homes have risen in value, something occurring across the country, not only lower their monthly payment with a lower mortgage rate but also take cash out of the house.

About half of the cash refi's are used for home improvements. The other half mostly tends to be used to pay for kids' college educations. And with the cost of college rising so much, this has got to be a major life preserver for a lot of families.

Berson says that $130 billion to $140 billion was taken out of homes in cash refi's last year, and of that about 40% was saved or used to pay off debts and about 60% was spent.

That means that about $80 billion of additional consumer spending was made possible.

Measured against the nation's roughly $10 trillion economy that is the equivalent of about eight-tenths of a percent of GDP, nearly a full percentage point in a year when the economy grew just 2.9%. No wonder Alan Greenspan, head of the Federal Reserve, keeps pointing out how important this has been in keeping the economy afloat.

How much longer can this keep going? The answer lies in another question: how much lower can interest rates broadly, and mortgage rates in particular, go?

Berson says the reason his refi outlook changed so dramatically is that the economy didn't rebound in the second quarter as expected and interest rates fell much more than expected. Now he says that the Fed may cut rates again which would help keep long-term rates low. And he sees the economic pickup getting stretched out so that mortgage rates will stay below 5.5% for the rest of the year.

Wyss says he thinks we are in the final throes of refi mania. While he's pretty certain the Fed will cut rates at the end of the month, because he thinks all of Greenspan's deflation talk is meant to telegraph a cut, he thinks that rates just don't have much lower to go from 50-year lows.

So, the message from the experts is, if you're thinking of refinancing, do it now! Don't get greedy, as so many have accused Ms. Stewart of being (perhaps unfairly) when she sold her Imclone stock in such a hurry. In other words, don't wait to see if mortgage rates fall further.

But do emulate Martha when it comes to taking action quickly when there is money to be saved. The mortgage payment you save may be your own.  

Kathleen Hays anchors The FlipSide, airing Monday to Friday on CNNfn. As part of CNN's Business News team, she is also a regular contributor to Lou Dobbs Moneyline.