Here's a few of the projects from the book How to be an Explorer of the World, which we were asked to do in one of our classes. Basically you are supposed to go out into the world and observe new things, do new things, and notice all the things you wouldn't normally see. Observation, categorization, and creation are the goals here.
One of the Explorations was something called accidental art- casually placed objects or functional objects that happen to look artistic. I think this is a great one for artists to pay attention to, since it provides you with interesting shapes/textures/compositions to draw. Photographers are usually best at finding accidental art.
Anyhow, here's a few things I found during the semester.