This is from Tom Kelley's "Ten Faces of Innovation":
Some opportunities are more obvious than others. To see how many exist in your world, try this exercise one day.
1. Write down every fix you see at work, at home or out on the town. Watch for things that are duct-taped or bolted on.
2. Look for add-on signs that explains what is broken or how a machine really works.
Give it your serious attention and you'll have taken an important first step towards sensing the rough edges of many current offerings. You'll have a better understanding of why some products or services truly sing. And you'll recognize when a product- or even a whole category-is crying for improvement.
If you are interested in innovation, I highly recommend this book. Tom does an outstanding job.