Many cell phone cameras, especially the iPhone, really start to shine when you bring them in close to your subject. The small sensor provides a relatively wide depth of field so you can get entire objects in focus where cameras with bigger sensors and longer lenses would have trouble.
When getting close, you can also usually have more control over the lighting of your subject. Are bright patches in the background of your composition throwing off the cameras meter and making your subject dark? Get closer and block it out all together. Small detail shots can be quite effective if done right.