The only upside of rainy days in the city is taking dreamy out of focus iPhone shots... What I really needed to do here was stand right in the middle of the street, but I was getting enough stares as it was on the corner. ;) I just can never pass up the opportunity to bokeh the great buildings of this city.
Many of you have figured out how to do this, but in case you still want to know how to create iPhone bokeh, there are two methods that are pretty much the same idea. The quick and dirty method is to compose your scene, focus on your hand close-up (sometimes I use the tip of umbrella when it's raining...) and quickly take away your hand and press the shutter before the iPhone has a chance to refocus.
The other is to use the iPhone's AE/AF lock. For this, I will try to focus closely on something around the same exposure as the scene, then hold down that part of the screen for a second or two. You'll then see "AE/AF lock" pop up on your screen. Then bokeh away! Fun fun.