The Boom, a pricey, hands-free headset for cellphones and some home telephones, is an example of how hard it is to be great.

Its foundation is the fabulous noise-canceling voice-recognition technology developed for use in brokerage houses and proven on the floor of the New York Stock Exchange, one of the noisiest places you'll ever want to call home from.

The technology was adapted for consumers with help from Frog Design, which has designed everything from cruise ships and motorcycles to faucets and the first Apple computer.

Even though it should be obvious, the secret weapon of a home entertainment system is its speakers. Many buyers focus on what they can see, either in the quality of the TV picture or, worse, in how a flat screen or other component blends in with the divan.

You can test this question of component supremacy for yourself, however: Pop, say, "Jurassic Park" into your DVD player and watch for a few minutes without sound. Then add sound and hide the screen and see which one gets your juices flowing.

One of the recurring minor questions of the technological age is, "Should we?"

Should we have, say, an electric blanket that can be turned on from the car 10 minutes before arriving home? Or a remote control that will pop corn while it's shuttering the windows for the 1:43 p.m. home-theater showing of "Rocky VI"? Should there be a "Rocky VI"? (Oh, wait. That's the subject of a different column. But no, there shouldn't.)

Do-it-yourself home designers used to have only graph paper and a ruler for tools, but you can find better tools these days on the Internet. The bad sites aren't that bad, and the best ones are getting better. jordansfurniture.com

A new software package by Hookumu Inc., a Salem, N.H., developer, could turn out to be one of the very best. It is due to debut by the end of this month on the Jordan's Furniture website. I got to test the package last week at home, and found it to be pretty snazzy: easy, efficient, and eminently customizable.

LOS ANGELES - What savvy actress wouldn't want to play Frida Kahlo, the Mexican artist and American pop icon whose 47 years on this earth would be unbelievable if they weren't true?

She survived a bus accident at 18 in which she was impaled on a metal rod - and nearly bankrupted her family during her convalescence. She began to paint as an outlet for her pain, which led her to a passionate and stormy relationship with fellow artist Diego Rivera; they married, divorced, then married again.

Make a rousing, hip, and funny film, and everyone thinks you have it made. All the right people return your phone calls, and the babies love you.

But with accolade comes expectation. And then comparison. If you want to stay on top, you not only have to make another hip and happenin' film, but it has to be even a little better.

Set against that backdrop, Jon Favreau and Vince Vaughn, whose "Swingers" surprised and delighted audiences five years ago, don't exactly have it made anymore.

For years, it's been this little lie played out between performers and audiences: At the "end" of the show, the act says good night and thanks for coming, and the fans stand and deliver their cheers, Bics and all, howling for more. Finally, the act comes back and delivers the rest of the show it was planning to all along.

The interplay depends on both sides pretending not to know what the other is up to, and it usually works. But last night at the FleetBoston Pavilion, the process broke down because Dennis Miller didn't like the weather.

Jerry Seinfeld didn't need to be especially funny last night to succeed before two sold-out crowds at the Wang Theatre.

So primed was the audience by nine years of one of television's most celebrated sitcoms that they started laughing at set-up comic Brian Reagan's material before he ever reached a punchline.

But it is a fact that Seinfeld is a funny guy. He was funny before the sitcom thing ever happened, he was funny during it, and he was very funny last night, practically from his opening utterance.

Robin Williams is a physical comic. Sid Caesar was a physical comic. But few people would ever give that label to Jerry Seinfeld, who barely had to move a muscle during the nine years of one of the most successful shows in television history.

Let's start at the top: Don Zimmer doesn't have a plate in his head. It's one of those "facts" that any moderately interested baseball fan knows, but it just was never so.