It is a well-known fact that consistent and correct use of condoms can prevent pregnancy. But condoms are not perfect. They've been known to break on occasion, and people don't always use them correctly. That's why doctors have recommended that they be used in conjunction with an over-the-counter spermicide for extra birth-control insurance.

But say the word "condom" and what comes to mind more often is its reputation as the method of choice for practicing safe sex. Condoms are now primarily used to prevent many sexually transmitted diseases, including HIV, the virus that causes AIDS.

In the late 1980s, nonoxynol-9, a product that has been on the market for more than 50 years and is the main ingredient in most spermicides, began to show promise as a method for preventing HIV transmission when it was observed to kill the virus in a test tube. The public and the medical community alike hailed N-9 as the newest HIV preventative, and many condom manufacturers hastened to lubricate their products with the chemical.