I know this is blasphemy to the photography gods, but I find myself wanting to use an iPhone over a DSLR simply for convenience. A DSLR is bulky and I don't have it with me at all times. The iPhone camera is getting better and better and can do so much with it that a camera cannot do.
Obviously you can't replicate DSLR quality with an iPhone (sensor size, lenses, low light capability, etc.) but convenience, weight, and size are big factors for me especially when traveling. Has anyone else given up their DSLR for an iPhone or do you use both?