Mac: Quicklook is an awesome feature that lets you quickly preview files without opening them. Here is a Finder hack that makes Quicklook even more useful: when you hit the space bar on a text document or PDF, you can select and copy text from the previewed document.
This is one of many Finder tricks posted by Mac Tricks & Tips. To set it up on your Mac, open a Terminal window and type:
defaults write com.apple.finder QLEnableTextSelection -boolean YES; killall Finder
To disable it, enter:
defaults write com.apple.finder QLEnableTextSelection -boolean NO; killall Finder
Hit up the link below to see 21 other Finder hacks. 22 Finder Hacks, Tricks and Changes [Mac Tricks & Tips]