One of the best things about finally having an iPhone is Instagram. I love it to pieces. Before, I would post photos from my iPod but had to wait until I had an internet connection to do so, and well, this is way easier. A lot of people are using PostalPix for printing their Instagram images, but I prefer printing them really small at home and using extragram.
It's a free, easy to use platform and a pretty fun way to look at a collection of Instagrams. Plus you can print photos from friends' feeds - instant and extra gratification.