Well placed wizz-bangery
I'm one of those people that read the release notes on new software to see what features are available to play with. Generally however, I forget about the wizz-bang cool stuff approximately 30 seconds after I read it and get excited. Apple are often criticised for form over function, playing up showy features at the expense of productive improvements. Amongst the aesthetically impressive stuff though, real gems of usefulness do creep in.
It's been a while since the "data-aware" feature was introduced into Mail, and I'd all but forgotten about it. Given the way it blew me away the other day, it might be worth rehashing this tale...
I received an email recently, confirming an appointment for the next week. It was a typically ugly business email, full of HTML gunk, including a huge signature with at least 8 typefaces and an image. For me to remember the crux of the email, without the bold, underline, black, blue and red distractions, I needed a new event in my calendar. When I hovered the mouse over the section of the email that stated the appointment date, a focus overlay appeared over the text that made up the date and I was presented with a drop down menu. When I selected the first of the two menu options, to create a new iCal event, the following appeared:

With no work on my behalf, a new event was ready with the subject of the email as the title, the location magically extracted from somewhere and the start time already entered. All I had to do was pick the destination calendar and click "Add to iCal".
Snazzy features that actually streamline your workflow are what make a computing experience enjoyable. This wasn't even a stretch for the data-aware feature, which is capable of the same given colloquial phrases like "this afternoon" or "tomorrow evening".