I bought my wife an iPad for christmas. The battery recharges via a USB lead, and a mains plug is provided with a USB port, so that you can charge directly from mains.
But the cable is ridiculously short — about one meter. It’s basically impossible to use the iPad when it’s plugged in, for fear of ripping the cable out of the iPad or the mains plug.
This is a very good thing.
It changes what kind of thing the iPad is. When I use a laptop, my default mode is to have it plugged in all the time, and just think of it as being able to survive for a while when isolated from its feeding trough. But with an iPad, the narrative is very different. It’s a device that isn’t wired into anything. It moves happily around the house with you, and just happens every now and then to need parking in its Special Place where the charger is.
Although these two usage models are identical in substance, the psychological difference is huge. I have been used to thinking of laptops as delicate super-powered entities that I must care for and love and cherish and worship. Whereas the iPad is just there for you. And since we’ve had it around, I’ve started to shift my attitude towards my laptop, too.
So the short charging cable is a clever piece of cultural engineering.