ghost_womanSnapchat, the real-time picture chatting app, couldn’t have chosen a better mascot. It’s a playful, cut-sheet ghost that speaks to the service’s impermanent nature, assuring users  their self-destructing messages and images are not long for this world, effectively transforming them into social networking ghosts.

Snapchat CEO Evan Spiegel championed impermanence at the Dive into Mobile conference yesterday, saying: “In this world, deletion as the default works pretty well,” and “We believe the default should be ephemerality.” Which raises the question: Would the Web be better if it weren’t so damn permanent?

Perhaps. Assuming that every image we capture, Tweet we compose, or Vine we record should last forever is the epitome of technological narcissism. The fact that your Tweet will make it into the Library of Congress is a fluke, not a sign of importance (although the fact that mine is is entirely justified, of course).

Pragmatically speaking, there’s a certain security in ephemerality. That’s why so many have called Snapchat the “sexting app,” and why jokes about Anthony Weiner and his glistening pecs never reaching the public’s eye if only he’d used Snapchat are so fulfilling, even if that’s a short-sighted view of the service.

Meanwhile, companies like Gryphn have built self-destructing messages into their own product, no nudity required. Snapchat now processes more than 150 million messages per day. People like knowing that digital doesn’t necessarily mean forever.

It seems like a mistake to discount permanence completely, though. Facebook, Twitter, Instagram, Vine; all of these services turn our lives into digital auto-biographies, allowing people to re-experience the past just as well as they enable sharing and social networking.

That’s why services like Timehop, a PandoDaily favorite that let users explore their Tweets, Facebook status updates, and Foursquare check-ins from one, two, and three years ago via an iPhone app and daily email, even exist. Timehop co-founder and CEO Jonathan Wegener recently told The Verge that the service is meant to be a home for online reminiscence. That can’t happen if everything we share is deleted moments after it was created.

Timehop’s daily update is one of the highlights of my day. It allows me to see what I was talking or thinking about three years ago. It resurfaces old pictures of my nephew that remind me how he wasn’t always able to run around and talk and, basically, function. It reminds me that I used to be one of those people who never used the “shift” key and relied on song lyrics to communicate (or irritate).

A move away from permanence and towards ephemerality wouldn’t allow for that. It works for some services — Snapchat key among them — but there’s something wonderful about services like Timehop that curate the past and, as Wegener puts it, become an online home for reminiscence.

They remind us of who we were a few years ago, before we became what we are today.

[Image courtesy BPAL Icon Collection]