Not sure if it qualifies as a "hidden gem" in OS X itself, but the new Signature management in Preview, using the built in iSight to scan a handwritten sig off a sheet of paper, is an amazing time saver.<p>// Number 8, bitesize.d, rocks.
Honestly, so far none of these have been the major performance bottleneck on my Macbook. For me, it's been RAM. Even though I have 4 GB of RAM, I have at least 3 GB wired or active at any given time - Chrome alone takes up roughly 1 GB of it, with all its helper processes. But unfortunately I really have no idea how to bring my RAM usage down.
One of the features that differentiated Macs from Windows early on for me was how they systemized PDFs. Not only could it read and write PDFs, it was eager to do so.
>> Why Unix? Mac OS X is Unix under the hood: the Darwin kernel<p>Just beeing pedantic but I think Darwin is the operating system, not the kernel. The kernel is Mach 3.
I once tried to look into dtrace because I was missing strace from Linux. I gave up when I realized I had to learn a whole language just to do what strace did for me on Linux.<p>Now I'm enlightened to see there is dtruss. It works different than strace and needs privileges, but I'm glad that I've found the strace alternative.