After my gripe yesterday that Amazon and Visa should work out a kink in their billing plans, I heard from a lot of readers who'd had the same problem. (Gist: Amazon charges 15 or 30 cents for Kindle-related fees; Visa flags these micro-charges as likely fraud and freezes your card.) Here's a sample reply, which also includes a sensible fix:

"The charges are doubly surprising, because for that small rate I suspect Amazon pays more in Visa fees than it gets in money.
"I'm surprised they aren't doing what Apple does in the iTunes store.  For a $0.99 purchase, Apple pre-authorizes your card for something like $10 and then, once your purchases accrue to a reasonable level, they actually run the larger charge on the accumulated purchases.  The only way they will end up running a 99-cent charge is if you buy a track and then don't buy anything more until the pre-authorization is about to expire."

After my claim a few days ago that we were still a long way from the day of the "all in one" electronic device -- camera plus phone plus e-reader plus netbook plus personal groomer etc -- Derek Thompson elaborates on his views, and a reader writes in, to similar effect:

"It's a debatable point, for sure, but I think your time horizon is a little short and have missed some recognition of how much the era has already arrived.

"Only a few years ago, no digital camera could match a 'real' camera, and we're already at a point that consumer point-and- shoots rival film cameras from 5 years ago, aside from the lens flexibility that most people don't need. Give it a few more years and you'll see 10 megapixel cameras in cell phones. And while you probably will never want to put a cellphone photo of mom hanging over the mantle, we've already reached the point where cellphones are rivaling dedicated cameras and camcorders for the *volume* of photos and videos taken.
"As Chase Jarvis will happily tell you, the best camera is the one you have with you, and it's just a matter of time before integrated cameras wipe out the consumer camera market. Remember, there are technological sweet spots on these things. Once you hit 10 megapixels or so, there's not much point of going further in the consumer space. You see the same things with audio, video, and even displays.

"The question isn't whether it's worse to read, worse photos, worse typing, but whether it's good enough or not. This isn't limited to electronic devices either. Paperbacks aren't as easy to read as hardbacks, the paper is thin and flimsy, the type is mushy, the text runs too deep into the spine, but they're good enough - either due to their size, cost, what have you that paperbacks have become extremely successful - so much so that publishers have to curtail their entry to the market in order to keep the more profitable hardback sales up. The real question is when will these devices catch up to the paperback, newspaper, magazine, camera, dedicated GPS, etc. in 'goodenoughness'  that they eventually kill off or seriously suppress the alternatives.
 "With the recent innovations in multi-touch and miniaturization/power reduction of critical components, I think that era is much closer at hand than you might realize."

My reaction is, We'll see -- and I say that as more than pure platitude. The nice thing about predictions of behavior is that sooner or later we'll know what actually occurs. For now I am skeptical precisely because I've heard about the impending "all in one" era for a very long time. Despite these predictions, I still see people carrying a cell phone/PDA (yes, these functions have merged), and a camera, and a computer, and sometimes a Kindle, and...  But, we'll see! And if all-in-one devices prevail, that will be good news, since it will indicate that future devices work better than I now expect.