An Enigma for the Future?

There is a neat book called Motel of the Mysteries, by David Macaulay. I thought it was long out of print, but even though it was published in 1979, it's still available on Amazon. If you're not familiar with the author, he has done a lot of wonderful books that explain, in detailed pen and ink drawings, things such as how the pyramids or a Gothic cathedral were built, or what you'll find underground in a city. Though most of his books are very factual, Motel of the Mysteries is quite different. It is a fanciful, but not far-fetched look at what might happen if an archeologist from thousands of years in the future excavated a late 20th century motel.
Basically, they misinterpret everything, thinking that toilet seats were some kind of headgear for a religious ritual, etc. It's an amusing way of making us question what we think we know about ancient civilizations.

The reason I was thinking about this was that I wondered if the checkbook will soon become obsolete. In a generation or two, will kids be as befuddled by checks as they are now by vinyl records, 8-track tapes and manual typewriters, to say nothing of items like washboards and butter churns? Online payments are becoming more and more popular for things that used to be paid by personal checks. Credit and ATM cards are accepted almost everywhere. I've read that in Japan, you can buy things from certain vending machines using your cellphone. And PayPal has made electronic funds transfers accessible to almost anyone.
Based on this, and on my unscientific findings in the recent "what's in your wallet" posts, you might also think that cash will soon be obsolte-- I'm not so sure about that. I think cash will be necessary and useful for a long time yet. But how often are checks really needed anymore?
I personally wrote exactly 26 checks in 2005. 12 of those were my rent checks, as I pay just an individual person, not a management company and I don't think I could set that up as an automatic e-payment with my bank.
The other 14 were as follows:
1 to attorney for condo purchase
1 to mortgage broker for application fee
6 for my French lessons, which I often just pay in cash
3 were transfers between banks-- I probably could have done this electronically, but might have had to pay a fee
2 were gifts sent to my grandmother
1 was a gift to my mother

This was down from 27 checks written in 2004 and 28 written in 2003. I was already paying most of my bills electronically by then, so I'd estimate that in 2002 and earlier, I was probably writing 40 or more checks a year.

Has anyone ever seen any statistics about the number of checks written each year? Are checkbook manufacturers going out of business? Will we all be trying to explain this to our great-grandchildren?

"Yes, Billy, people used to keep a little book of paper sheets that were sort of like play money, but you could turn it into real money by writing your name on it and handing to a person who sat behind a window!"
"And you had to write it down every time you gave someone one of the little pieces of paper? And sometimes you weren't sure how much money you had? That's weird, Grandma... hey, can you put $500 on my brain-imbedded credit chip so Tommy and me can go get Popsicles?"