My Giant Calculator

Date: 2005

Date I purchased the HP11c that I inevitably use instead of my phone or a computer: 1989. The user interface is better, so much so that I'll spend several minutes obtaining it to do thirty seconds of calculations. Perhaps so I don't look at the new email, current HN frontpage, or feed on Facebook.

Which OS offers a calculator from the top menu bar? Definitely not OSX.

By the way, you can do this with spotlight: cmd+space, type and see result instantly, ESC to close