It's something very cool that I didn't know: did you know that Mac OS X keeps recent records of when your MacBook (Air / Pro) was opened? Great for plant paranoids who want to know if there are any eavesdroppers around.
To do this, open the Console (located in the / Applications / Utilities / folder, or you can quickly use Spotlight Command + Spacebar to find it) and select the option kernel.log in the side column, inside FILES.
A large record will be shown on the side; to filter only the laptop lid opening, type Wake reason: EC.LidOpen in the search.
Ready! Date and time of every time your MacBook (Air / Pro) was opened and taken out of mode sleep.
The number of items shown depends a lot on the intensity of use of your machine, how many errors it generates, etc.
Here, I got to see it up to a week ago.
(via TNW)
