Keep two kinds of extra-virgin olive oil on hand

Dear Martha: How do the grades of olive oil differ, and which kind should I use for everyday cooking?

A: Extra-virgin olive oil, made from the first pressing of olives after harvest, has a bright, fruity taste. Neither heat nor chemicals are used to extract the oil (hence the labels "cold pressed" or "cold extraction"), so it is the freshest and the most healthful olive oil. Virgin olive oil is also extracted without heat or chemicals but is more acidic than extra-virgin and may not be from the first pressing. Bottles labeled "olive oil" or "pure olive oil" typically contain blends from second or third pressings, with virgin or extra-virgin oil added for flavor.

In the past, the price of extra-virgin olive oil limited its use, but affordable bottles are now widely available and are even preferred. Ideally, you should keep two kinds of extra-virgin oil on hand: an inexpensive one for cooking and a premium one for dishes that will showcase its nuanced flavor and aroma. Both characteristics diminish when an oil is heated, so use the everyday one when sauteing, grilling, making sauces or baking. Serve your best oil drizzled over roasted vegetables, whisked into a vinaigrette, tossed with pasta, or simply on its own with a loaf of crusty bread.

Oils can turn rancid with exposure to heat or light, or simply with age. To prevent this, store olive oils in a cool, dark place; they will keep for about a year.

Dear Martha: With all of today's technology, what is the trick to staying focused?

A: We're overcommitted to media, handheld devices and computers, and sometimes we have to take a break. The best thing to do is to devote a time of day to managing that communication.

My work and home computers, BlackBerry and iPhone get the same e-mail, so I'm pretty connected. I look at the computer when I get up in the morning and answer any e-mails that came in during the night. The next time I look is when I'm in the car on the way to work. But don't do that if you're driving!

I also keep a notebook where I jot down notes and minutes from the day's meetings. (If I write on a stray piece of paper, it may go astray.)

Staying organized is important, but there's an etiquette, too. You shouldn't check your e-mail at lunch with friends.

Dear Martha: How did flower frogs earn their rather peculiar name?