Teach Your MacBook the Difference between Sleeping and Hibernating

Sleep mode on a Mac is great, usually. Your laptop goes dark right away, and all your data will be kept in RAM, making it a snap to get back to once you're ready to work again. The only problem? Sleep mode drains your battery ever so slightly; if you underestimate your time away from a plug, you could be in trouble. Enter SmartSleep, a cool new (free!) program that tells your MacBook to stay in sleep mode until the battery hits 20%, after which it sends it into hibernation mode. Just remember: if you want to swap out your battery, you can't do it in sleep mode! (via LifeHacker)