Preview is one of the most useful parts of Mac OS X: having a lightweight, fast and broadly compatible tool for displaying visual media is one of the main reasons that the Mac OS offers the best user experience of any desktop OS. For most people, displaying pictures and documents is all Preview does, however if you scratch beneath the surface it has some great features which can save you a bunch of time.
Preview as an eReader
I find myself being sent long PDF formatted eBooks with increasing frequency these days. Trouble is, reading on a computer screen can often be distracting (it’s amazing how interesting your clock and battery percentage become when you’re trying to read something challenging). Preview has a built in ‘presentation mode’, which allows you to read in full screen without any distractions.
To activate presentation mode, hit ‘CMD-Shift-F’ in Preview and read away.