Letter writing an obsolete skill?

I caused quite a stir in the teacher's lounge the other day when I shared the light bulb of inspiration that had illuminated my poor little archaic brain earlier in the day in the classroom.  One of our most worked on and most emphasized writing standards in second grade is writing a friendly (as opposed to business) letter.  You know, that piece of writing from one person to another on a carefully chosen stationery,  then slipped into an envelope, stamped, driven to the post office and personally delivered by postman to the cherished friend.  The students I am teaching, I realized, would probably never use this skill of writing a letter.  They don't need to know the five parts: date, greeting, body, closing and signature.  Because they call, they email, they text, they twitter and they, yes, blog! But they don't write on paper.  I used to love roaming the aisles of the local stationery store, thoughtfully considering the choice of stationery, sealing wax, and pens.  But now the kids wallpaper their cell phones, and put badges and widgets on their social networking pages.  Teaching them to write letters is like teaching them how to look up information in an encyclopedia.  Obsolete!  But we do still teach it, and we teach them how to look things up in an encyclopedia, even though no one even owns an encyclopedia (how proud I was to be able to spell that word in second grade!)  We should be teaching them about privacy settings and how to edit in html and all kinds of other things that I don't even know that I should be teaching them.  Maybe it's me that is obsolete...