1/ Spotlight does more than search; including converting from US dollars — By clicking on the magnifying glass in the upper-right corner of your screen (or press the keyboard shortcut ‘Command-Spacebar’), you can do conversions of many different types, from currency to cooking. For example, if you type in a dollar amount, Spotlight assumes US dollars but knows where you are and immediately displays the NZ equivalent (above). Or start with the British pound symbol (Shift-3).
2/ Convert more than currency — Some other conversions available are temperature (by typing in something like “85F” or “650K”); weight (“540oz,” “25kg,” or “23 stone”); and measurement (“54yd” or “567mm”). If there’s a specific conversion you’re looking for, you can try typing that in instead (ie 6 yards to centimetres’ or even “6yd to cm”, as this works with either abbreviations or with the typed-out words.
3/ You can merge Calendars — Sometimes you end up with too many calendars,l but you don’t want to lose any events. Assuming you have your Mac backed up, as we’d hate anything to go wrong (or at least that you have your Calendar backed up), Open the Calendar program. From the list on the left, select the calendar you’d like to export the events from to merge together. From the menus at the top, choose File>Export>Export (shown below).
Save the resulting file out somewhere on your Mac. Now, within Calendar, choose File>Import, and then pick the .ics file that you just saved out. A pop-up window will appear, asking you which calendar you’d like to import the events to. Select OK afterward, and you’re done – the events from your exported calendar will merge with whichever one you chose, and then you can safely delete the original calendar by selecting it from the sidebar and pressing Command-Delete.
(In older versions of OS X, this process would duplicate events onto the calendar you imported them to. Under Yosemite with iCloud, however, this now moves the events to the new calendar, so you’ll see them disappear from the original. To make sure you’ve gotten the events where you want them to go, you can deselect all but one calendar from your sidebar and examine them each in turn.)
4/ Swap files between user accounts — Some people have several ‘User Accounts’ set up on their Macs. That means several people (a couple, kids etc) can use the same Mac but keep their files separate, since you have to sign in to each account to see them. But how, if you don’t know each other’s passwords? Apple provides a Shared folder inside the Mac’s Users folder (found at the root level of the startup drive).
The Shared folder’s permissions are Read & Write, across the board. Anyone can put (or copy, by Option-dragging) a file into here, and any other user can see and open it. This saves all that messing about with USB drives.
5/ Hide others — Often, you have so many things open, you can get a bit confused as to what you’re working on or even looking at. I love this simple command combo that hides everything except the ‘frontmost’ app – in other words, the app that’s running and using resources immediately, which you can see by looking at the app name next to the Apple menu at top left of your screen. This is it: Command-Option-H. In other words, while you are holding down Command and Option together, which I can do with my left thumb, press the H key. Instant clarity. This doesn’t quit anything else, it just removes them from view.