For long-term mac users, this may seem ridiculous. For those converts from the PC universe, be prepared to have your world rocked. Spotlight is Apple’s search feature built into OSX, and if you’ve converted from a PC throw all ideas about how search on large file systems works out of the window.
Without going into mega-geeky details, the way that the Mac formats hard disks allows for incredibly quick search (instantaneous in comparison to the PC). Just click your little magnifying glass at the top right of your screen, type what you’re looking for an voila; (in 1-2 seconds) it’s there! Emails, applications, text files, images… everything!
And here’s the best part: it searches the contents of files as well as filenames! There are lots of other tools that seek to improve on spotlight. I’ve tried them, but keep coming back to spotlight because it is so solid, and it’s on every mac at which I sit down.