I was researching effective blogging techniques when I came across this advice: "If you've never visited PostSecret it's one of the few sites on the Internet that is actually worth a damn and does something to change people's lives."

I'd seen a reference to PostSecret a year earlier and had glanced at it but then moved on. This time I took a closer look at the photoblog and was immediately drawn in. The site describes itself simply: "PostSecret is an ongoing community art project where people mail in their secrets anonymously on one side of a homemade postcard." But don't expect the "Having a great time, wish you were here" sort of touristy postcards; these are handcrafted works of art, revealing photographs, unusual and declarative pieces of paper, and more. The image is as important as the text, as are the interplay between the two.

All the cards' elements combine to represent secrets intended to be something never shared with another person — but often they are secrets that their senders have never even admitted to themselves. People have reported dropping their postcard in a mailbox and feeling freed or released from their secrets; others, once seeing their secret manifested, have destroyed the card as a metaphor for no longer being the person carrying that secret. Still others never let their secrets — or their postcards — go. Altogether, it's a sort of anonymous group therapy: whether the secrets are scary, funny, commonplace, or depressing, they are all about humanity — and in that, we all find something to relate to. Though I could empathize with many of the secrets, I was stunned when I found one the text and image which were impossibly unique to me — a secret I've told only two people. To know there's someone else out there who sees him- or herself the same way I do myself made me feel a bit less alone.

PostSecret's founder, Frank Warren, updates his Web site every Sunday with 20 never-before-seen secrets; and once a year, he compiles these and others into a hardcover book. It took only a month of weekly Web site visits before I went to the bookstore to buy the thickest compilation I could find — when I was done with that, I lent it to a friend, then went back to the store to buy myself more.

Last month's release of a fourth collection coincided with Mr. Warren's visit to Boston for a signing at the Harvard Book Store. He preceeded the signing with a 45-minute presentation about the origin and nature of PostSecret. During this talk, he also shared with us many postcards that, for various reasons, he's otherwise unable to distribute. And he took the audience into his confidence when he related the fourth-grade secret that he often attributes PostSecret for revealing and allowing him to overcome.

As he told jokes, took questions, and related stories, I was surprised at how thoroughly Mr. Warren's demeanor defied my expectations. When it finally came time for him to sign my book, I felt a bit silly that I mutely stood there, wanting to engage him in conversation but not wanting to take up his time. Finally I blurted out: "I'm trying to think of something clever or witty to say, but I'm drawing a blank. You've probably heard it all before, anyway. But I gotta say, you're far more optimistic and cheerful than I expected. I bought one of your books that someone else had stuck their secrets into, and I was overwhelmed with the responsibility of what to do with them. And here you are with 200,000 postcards, laughing and smiling."

His response: "If you've lived the kind of life represented in these postcards, then you may be more inclined to see them not as a burden, but as solace."

With a line behind me, I knew the conversation had ended, but I was rooted to the spot as I tried to figure out if his answer made me feel fortunate, or guilty. He gently smiled, said "Thanks for coming," and left me to contemplate more than the secrets in his new hardcover.