Your spacebar is an excellent timesaver on your Mac if you know how to use it. One great use is open spring-loaded folders in an instant.
If you're not familiar with the concept, your Mac's folders are spring-loaded by default. This means that when you drag something on top of them, they'll open automatically if you just wait a few seconds. If you aren't feeling particularly patient, however, just press the spacebar. Doing so will cause the folder to open instantly. Check out the video above for a demonstration.
Your spacebar has plenty of other functionality, too. You can use it to zoom in on windows in Mission Control and even to click. Hit up the full post over at MacWorld for an overview of some other great ways your spacebar can make you more productive.
Five unexpected uses for the spacebar [MacWorld]