A good friend of mine sends out a brief monthly email, summarizing what he's been up to, the movies he's seen and the music he's listened to. It is something I look forward to receiving.
This was often done in the past via "Christmas Letters," or other annual (or semi-annual) letters. A family would write a one- or two-page letter detailing their major life events and experiences since their last letter, and send it to friends and family they haven't seen or talked to much.
Sending them is a good way to keep in touch with people you wouldn't normally, and receiving them is nice because you can feel like you've never fallen out of communication with your family, even if the Christmas Letters are the only kind you get.
It's not quite the same, but a circle of college friends have a long-running email thread which we use for this purpose. Everyone usually sends a "What I did on the weekend" email update on monday morning, then random tidbits/links/experiences over the week.
It's a great, casual way to stay in touch with a lot of friends. A few I keep in touch daily through GChat, but the others I depend on the email chain. I look forward to Monday morning to read what everyone did over the weekend.
There's definitely some merit in the idea.