Snapping a quick photo on the go is pretty easy and convenient with the iPhone, and the quality is decent in well-lit, outdoor settings. I downloaded an app called "CameraBag" that applies filters to the photos to make them appear as if they were shot with different makes and models of vintage cameras. The results are impressive. Below I've included the original, and the various versions. The app costs $2.99.
The Original Unedited iPhone Photo
The Vintage Helga Filter (with vignetting)
The Lolo Filter (wth border)
The 1974 Filter (with border)
The Vintage 1962 Filter
The original iPhone photo and the 1974 filter (with border)