Update Day
Apparently, π day is also update day.
I plugged my iPhone 4 into my laptop this morning, wanting to back it up.  iTunes  informed me that an iOS upgrade was ready. I said yes, but then was surprised to find the estimated download time at over 40 minutes. Not having time right then, I cancelled, without any fear of damage.
I later discovered my phone had done an OTA download over Wi-Fi somewhere, and I could simply let it upgrade itself while I pulled out the laptop and fired up Word 2010. Except that Word decided it needed to “reconfigure itself”, stealing several minutes of productivity. I had no choice in the matter; no opportunity to cancel.
Good software never forces a period of unavailability on its users. Enough said.