This is a great little trick if you have a MacBook Air or one of the retina MacBook Pros.
To save battery, Apple now puts these computers into a deeper sleep after a pre-defined period of time. Unfortunately, this means there is some lag when you open your laptop. The problem is compounded when you put your computer to sleep plugged into a monitor with a different resolution. When your computer wakes it shows an image of the old screen at the old resolution making things look strange and slightly broken for a few seconds.
You can change this by delaying the deep sleep function. To make it work, open Terminal and type in:
sudo pmset -a standbydelay 43200
This delays deep sleep for 12 hours. You can change the time to anything you want using the math:
You can find a longer explanation and the source of this tip here. I have noticed some increased batter drain. I have also, of course, noticed a huge improvement to my wakeup time and user experience. My laptop is back to feeling much more like an iOS device.
Edit 2013-03-27 - I decide that 12 hours was too long. I am now using three hours:
sudo pmset -a standbydelay 10800
Here is a link to a detailed technical article explaining the background behind this "trick."