This is a simple exercise you can do anywhere, that will help develop your photographic eye. Take your DSLR camera with just one lens and go for a walk (this applies to any point and shoot camera as well). While walking down the street, strolling in the park, out hiking etc.., stop occasionally and find something to photograph say within 10 or 15 feet (3 to 5 m) from where you are standing.
If you are out walking with a non photographer, ask him or her to tell you when to stop. Look up and down, look all around you, take your time to find something interesting to photograph. It can be a scene that is happening right in front of you, an architectural detail, a bridge, building even an insect on a flower. If you are using a DSLR try using just one lens but experiment with a different lens each time to make the exercise more interesting. The aim is to learn how to make the ordinary look extraordinary. Try different angles, a shallow depth of field, etc. Or experiment with your images in the digital darkroom later!
Why not get children involved in this exercise. This is a perfect way to get them to exercise, and introduce them to photography at the same time. Their discoveries might surprise you!
The possibilities are endless; just remember to have fun & experiment with your photography.