Interest rates on savings deposits are crashing. "The downward momentum is fierce," says Bob Heady of the Bank Rate Monitor, who surveys banks and savings and loans in the largest cities every week. In early June, he found rates on some money-market deposit accounts dropping close to the level of old-fashioned passbook accounts.

Compared with a year ago, you are probably earning 25 to 28 percent less on the savings you keep in banks.

According to the survey, average money-market deposit rates sagged to 7.28 percent, with the big Detroit banks down to 6.85 percent. Average six-month certificates of deposit stood at 7.83 percent, with New York banks high at 8 percent. Average 2 1/2-year CDs paid 9.2 percent and five-year CDs, 9.8 percent.

That's the bad news for savers. The bad news for borrowers is that lending rates are still hanging fairly high. The banks are a lot quicker to cut the rates you earn on savings than they are to reduce the cost of loans.

Since last August, savings rates in the major cities have dropped by an average of 2.4 to 3.6 percentage points, Heady says. Over the same period, mortgage rates at the major thrifts fell by 1.6 to 2.2 percentage points, while auto loans dipped by less than 1 percentage point. Credit-card interest rates haven't moved at all. In a few cases, in fact, the banks actually have increased credit-card rates and fees.

Bankers always struggle to keep lending rates high for as long as they can to beef up profits. But sooner or later, they have to crack. "Banks usually drop savings-deposit rates as a preparation for dropping lending rates," Heady says. "They hope you'll be grateful for getting a cheaper loan, without noticing that you paid for it first by getting less from your savings deposits."

If the sharp slide in savings rates is a signal, borrowers should be seeing noticeably lower loan rates pretty soon. If you can put off closing your house or car loan for a short time, the odds are you'll get a better deal.

For home buyers, the lowest interest rates generally can be found at mortgage companies, according to data published by the Federal Home Loan Bank Board.

On conventional fixed-rate mortgages, mortgage companies charged an average effective rate of 13.4 percent in early May, compared with 13.6 percent for savings and loan associations. On adjustable-rate loans, the mortgage companies averaged 11.3 percent, compared with 11.5 percent at S&Ls and 11.8 percent at commercial banks.

Those averages, of course, are very broad. On individual loans, the savings at mortgage companies -- on both interest rates and points -- can be much larger.

The BRM survey picked up two developments in adjustable-rate mortgages.

First, banks are pricing them less attractively. If mortgage rates are going to fall, many lenders would be pleased if you locked yourself into a fixed-rate loan. And second, some lenders are raising the caps that restrict how high the adjustable rate can rise. So even if you get a good rate today on an adjustable loan, you might have less protection if interest rates rise again substantially.

If you qualify for a loan backed by the Veterans Administration, you can now get a fixed-rate mortgage at 11.5 percent and a home-improvement loan at 13 percent.

Strong competitors for your home-improvement business are the new home-equity loans being offered by many banks and some major brokerage houses. You borrow against the value of your house, at an interest rate that floats 2 to 2.5 percentage points above the prime rate -- resulting in a cheaper loan than is available today through the VA.

In the months ahead, the smart borrower will call more lenders than usual when shopping for a loan. Some will be dropping their interest rates faster than others, or be more willing to waive up-front fees. A little time spent looking around should save you a lot of money over the term of the loan.

The only holdout will be bank credit cards. The banks are expected to go on charging sky-high rates as long as consumers are willing to pay. Now costing an average of 18 to 20 percent plus annual fees, these cards have become so profitable for lenders that credit-worthy customers are getting letters from banks nationwide, begging them to sign up.

To get you to buy, card issuers are dangling a cornucopia of inducements, such as accident insurance, catalogue shopping and access to a health club in certain cities, just in case you travel there. But your best strategy today is to cancel old cards rather than sign up for new ones -- at least until you're offered the only inducement worth having: a decent interest rate.