There's a quote that says, "The best camera is the one you have with you." It's attributed to photographer Chase Jarvis, and is a great reminder for photographers (and everyone) that it's not always about having the best camera or latest gear. Sometimes it's more important to be able to capture a moment as it's happening, or photograph a scene before it's gone.
For serious, intentional photography, I definitely favor my Nikon DSLR and the variety of settings and lenses available. But with the camera comes a large bulky bag, and it isn't something I keep with me all the time if I'm not planning to take photos. I do always have my smartphone with me, though. I chose my phone partially because of the great camera it has. So if I happen across a scene that begs to be photographed, I'm prepared. Using a smartphone or other "simpler" camera rather than my big DSLR also forces me to focus on finding an interesting subject and composition to create a strong image.
So here's a compilation of photos I've taken on my phone because it was the only camera I had with me.
Bonus: Without camera phones, I wouldn't have this cool picture of me with a giant leaf.