Instead, mortgage rates actually rose significantly, reminding everyone that changes in the federal funds rate do not directly control the direction of mortgage rates.

Now that the Fed has cut rates by 75 basis points, it's anyone's guess where mortgage rates will go. But Richard DeKaser, chief economist for National City Corp., is betting the cost of carrying a mortgage won't be going down substantially any time soon.

"We've seen the lowest for mortgage rates," he says. "We're going to be in the range of 6 percent for the balance of the year."

Time may prove DeKaser right. If so, consider yourself a winner if you locked into a mortgage before January's rate cut, when mortgage rates were near historic lows.

This will be a boon for countless Americans with subprime mortgages who fear their next reset could leave them facing foreclosure.

"The Fed's actions in their own right are going to reduce the burden of mortgage resets," DeKaser says. "So that will help directly."

Of course, not everything was rosy. The U.S. credit crunch and falling home values made it difficult for some borrowers to take advantage of sinking rates. Nonetheless, many homeowners and homebuyers had a window of opportunity to lock into historically low borrowing costs for many years to come.

For now, it appears that window has slammed shut, leaving those who failed to act earlier feeling like losers.

The moral of the story is simple: Don't make mortgage decisions based on Fed actions, such as this week's rate cut. Instead, take the appropriate action given your individual circumstances.

"Trying to time the market is historically a fruitless exercise," says Bob Walters, chief economist at Quicken Loans. "If it saves you money to convert your ARM or to lower your fixed rate, then by all means do so."