I was firmly in the anti-card camp, but I've found things have changed since having a kid. Suddenly photos of the littleun are a commodity for relatives - especially the older and less internet savvy kind. So, I've been sending cards using pictures of my son to people where in the past I might have a) sent a crappy off the shelf card and hated the whole process and b) not bothered through apathy.
One thing that kick started it all was finding a program called Comic Life (Mac users - I recommend it heartily) which is great for knocking up comic strip style cards using my own photos. I've also been known to send an occasional e-card as a slightly more colourful way of marking an occasion than just sending email. I think cards for me inhabit a sort of middle zone of contact with someone, and I find it pleasing to think that I can send my offline relatives something tangible with a picture of their grandson/great grandson on it.