I feel like I am making some sort of confession here: Yes I am a professional photographer, yes I use hipstamatic on my iphone...
In the past I've talked the importance of a photographer having a visual diary, a place to record daily images that are just about what you are thinking and how you are feeling. That's what I've been using the camera phone / hipstamatic combination for the last couple of months and I have put some of the pictures up as a gallery on my archive (here).
I've chosen hipstamatic because I like the set it and forget it aspect. In that it reminds me of shooting with a Dianna camera, one setting, what you get is what you get. Instagram (which I often use to upload) makes me look at the phone too much. With a visual diary I want to be looking at the world around me, not at the back of my phone.