After teaching Interactive Media Production at the Miami Ad School for a couple of months, I realized that the best possible way to ensure you're working on something meaningful— something that matters to you and others—is to ask yourself whether you're solving a problem through your design. This is also the best way to find new things to work on. Keep a small journal and everytime you're annoyed or angered by something write it down.
I was at Whole Foods on 3rd and Third the other day and (sidenote: you must go to there) I was thinking, 'I wish there was an easy way to know what fruits and veggies are in season right now so that I'm able to eat fresh and local as much as possible.' So, I made Seasonabl.es, a responisve site that quickly tells you just that: what's in season, in New York, right now. (More locations coming soon!)
Chances are great that if you're experiencing a problem, so are several other people. As a designer it's your duty to use your talents to solve these problems in the world. As the legendary Stefan Sagmeister says, "Complaining is silly, either act or forget."