One day this fall, I spent the better part of an afternoon strapped to a chair, electrodes all over my body, with an 85-pound Indian woman superheating a metal plate, touching it to my skin and asking me to tell her (1) when I felt pain and (2) when I wanted her to stop.

Not surprisingly, my responses — “Yes, it hurts” and “I’d really like you to get that thing off me” — came very close together. I was participating in a clinical trial — one day it will surely take the medical community by storm: “Pain Hurts,” the headline will read — for cash, enduring this discomfort to earn a whopping 25 bucks.

The real torture came afterward, though, when I checked my “status update” feed on Facebook. While I was proving that fire burns skin and trying to concoct the perfect, effortlessly witty yet decadent way to describe the experience, my friends were doing things that I could only dream of: Jacob was “skydiving,” Marie was “polishing her husband’s Emmy” and Nate was “closing a deal with ABC.” I had just spent an afternoon experiencing life as a human shish kebab, and here was yet another series of intimidating status postings that made me nearly confess to the world, “Patricia is considering plagiarizing other people’s Facebook updates so her life won’t seem so pathetic — which is, sadly, even more pathetic.”

The rapid growth of social networking sites — the combined number of users of MySpace and Facebook alone would create the fifth most-populous nation on Earth, and that’s not even wading into the various Web sites that connect people with common interests in books, music and other hobbies — has greatly increased opportunities to interact with friends and strangers online — and to envy them.

The underlying truism to the saying “The grass is always greener on the other side of the fence” is that appearances are deceiving. But since Facebook has added a new level of voyeurism to surveying your neighbor’s yard, I find myself wondering, more than I would like to, whether other people’s lives really are better. After all, we have access to our friends’ photos, videos and correspondence — most everything but their tax returns — which tend to support whatever claims they’re making. If Casey’s update says she “is living in paradise, being waited on hand and foot by a league of celebrity look-alikes,” chances are that pictures will follow.

And not only does Facebook allow users to “verify” their friends’ claims, it also delivers with immediacy. In the old days, we got updates on friends’ accomplishments at reunions, through the ubiquitous Christmas newsletter or during an annual “I am sorry it’s been so long but really it will be a year before I ring you again” call. But Facebook, with the click of the “refresh” button, indulges my little green-eyed monster 24 hours a day. Tired of hating the friend who ate a dozen cupcakes and doesn’t know how she didn’t gain weight? Another friend just happens to be “packing for a trip to the international space station.” It’s kind of like watching a stock index of people’s lives, but in a perpetual bull market.

During the presidential campaign, I confess that I found myself putting more thought into my status updates than deciding whom to vote for.

When I am at a loss for something exciting or positive, I go for the innocuous, bordering on inane: “Patricia thinks clouds are icky.” It helps, of course, when something big happens in the news. But most of the time, I am left to my own devices. Patricia is wondering if VHS will make a comeback? Patricia remembers “Space Chimps” — do you? Sometimes, sharing the truth with my Facebook friends is about as appealing as the thought of Mahmoud Ahmadinejad serving as the grand marshal of a gay pride parade.

As my sympathetic Facebook friend Elizabeth observed, “It always seems like there’s a party going on and I’m not invited.” It reminds me of junior high when the popular kids showed up on Monday talking about the crazy, fun things they did over the weekend and I’d spent the previous two days mistakenly thinking that fractals were cool.

If Facebook had existed back then, my updates would have read, “Patricia is starting to realize that Andrew McCarthy isn’t likely to love her the way she loves him” or “Patricia is trying to convince her mother that dashikis simply don’t go with her ‘bandana over hair curlers’ look.” Then again, my present-day updates aren’t much better: “Patricia is wondering how much she could get for a box of gaucho pants on eBay.”

Thanks to Facebook, I’m developing an inferiority complex checking out the greenness of other people’s grass. I wonder if there’s a status update in noting that my apartment building is landscaped with Astroturf.