Seems I'm not alone in doubting that e-wallets will eliminate the leather variety any time soon, as many of you have written to add to my list of wallet contents that even the smartest of mobile phones might find difficult to replicate.

One such e-mail, from Ken Johnson, an IT guy at Businets in Fredericksburg, Va., carried the subject line: "What's in my wallet?" And provided this answer inside: "Everything you described plus a spare house key and a John Wayne can opener."

OK, an e-wallet could replace the key, but a John Wayne what?

He had attached a photograph (right), and, upon opening the file I could only gasp and send this reply: "Tell me that bad boy is not really in your wallet. Joke, right?"

Joke, wrong.

"Really, I've had that thing in my wallet since I was a corporal in the Marine Corps."

So I asked the most obvious question next: How does this barbaric-looking thing live in one's wallet without becoming a weapon of ass destruction?

"It folds flat and is thinner than the house key."

Phew. How long have you carried it there?

"Twenty years, easy. I believe one came in every box of C-Rats (and at one time, so did a pack of 4 cigarettes). I was in the Corps from 1971 to 1991."

And since then this John Wayne has come in handy when?

"Camping mostly. But I've used it at a customer site when they were trying to open a can of coffee and the can opener broke. I probably sealed the deal with that little helping hand."

So what connects this wallet-sized can opener to the Hollywood legend after whom it is named? There is, of course, a Wikipedia page to explain:

The P-38 is known as a "John Wayne" by the U.S. Marine Corps either because of its toughness and dependability or because of an unsubstantiated story that the actor had been shown in an as-yet-unidentified training film opening a can of K-Rations. The can opener is pocket-sized (approximately 1.5 inches, 38mm, in length) and consists of a short metal blade that serves as a handle (which doubles as a flat-blade screwdriver), with a small, hinged metal tooth that folds out to pierce the can lid. A notch just under the hinge point keeps the opener hooked around the rim of the can as the device is "walked" around to cut the lid out. A larger version called the P-51 is somewhat easier to operate.

Whether that one fits in a wallet was not revealed.

That it is unlikely to be rendered obsolete by a mobile phone goes without saying.

(Please feel free to use the comments section to let us know what's in your physical wallet that may prove irreplaceable by an electronic one.)