A little while ago, I bought a couple of nifty stands for my iPhone from Piolo. There’s not much to them, really: they are just a nicely molded piece of plastic with a slot in one end just wide enough to grip the edge of an iPhone 4 without a case. The idea is that you attach the Piolo to the edge of the phone and you can prop it up in either portrait or landscape mode. It’s simple, sturdy, light and just works. The nice thing is that you can slide the Piolo up or down the edge to adjust the angle of viewing, and it works well in lots of different situations.
They are pretty cheap (and made in Sheffield!) so I bought a twin pack of yellow and cyan so that I could keep one at home and one in my bag to take to work and so on. The stands are small and light, and even have a hole in one end so that you can attach them to a keyring or something similar. Sometimes the simplest little tools can be very satisfying.