How many electronic devices do you use regularly? When you go to a conference or attend a meeting, the first thing participants ask for is Internet access -- and then coffee. So organizers estimate the number of participants, add some tolerance and then order a certain number of WiFi accounts. When you look around, almost everybody uses a laptop. But people have a laptop and a tablet. So you should double the number of accounts. And then almost everybody uses their smart phone, too. Which triples the original estimate. I don't have a smart phone, but I too travel with laptop and tablet (mostly because I always have to prepare some longer texts for which I prefer a real keyboard and Emacs -- while you can use an external keyboard with an iPad, Emacs is not available for iPad).
When I survey my home office, I discover a high number of computers per square meter: A black MacBook from 2004 named Heinz, a MacBook Air from 2008 (the rounded-edge model) named Marlene, a MacBook Air from 2013 (the sharp-edge model) named Fred. Then there is my partner's late-2008 model MacBook (named Themis) and a Celeron PC running NetBSD (named Eurus) we use for scanning -- so we do have a scanner, too (no name for this one!). All in 10 square meters. We have a cable modem, which is connected to an AirPort Express wireless router named Horst and a printer named Gaia also connected to the wireless network via a second AirPort Express named Gunther. And then there are Fräulein Meier, the iPad, Laurin, the iPad Mini, Tippse, my Apple Wireless Keyboard, and Berta, my Nokia phone, floating about the entire apartment. That's a lot and everybody is talking to everybody via WiFi or Bluetooth! And in a corner, there is still Herbert, my old Toshiba Satellite notebook from 2001.
I use Heinz for iTunes mainly, I haven't quite finished the migration from Marlene to Fred yet -- Marlene was kind of a lemon, she got a new SSD, but this didn't fix the unexpected crashes and her refusal to install updates. At my previous jobs, I always had a computer, too. As I sometimes had several employments at the same times, this almost doubled the number of computers I used regularly: A Sun and later an iMac (with alternating names because of network changes) at the University of Zurich, a Dell laptop at the University of Applied Sciences Northwestern Switzerland named Waltraud, and after that an iMac at the University of Basel also named Waltraud.
Switching computers requires data management, like deciding where and how to access e-mail messages, and where to store documents -- I used the versioning system CVS with the repository stored on the network at UZH, so I could check out and commit drafts from anywhere. In Konstanz, I decided to use only Fred and not another computer -- I'm also running out of names, but more on this next week -- and asked for a big screen only.