Writing is hard. Writing consistently (say daily) is hard too. Some people (I'm thinking Seth Godin, Valeria Maltoni, Chris Brogan) make it look so easy; they dish out fresh new content almost every day.
The idea here is to sift through the magazine in search of headlines and post ideas.
This exercise works so well because it forces you get get out of the cave you call an office and to get some fresh air. This can often lead to creativity especially if you're out there interacting with new people. The change of atmosphere and change of pace (heck, the change of everything) almost always leads to new inspiration. But make sure you have that note pad handy otherwise it's a waste.