o's. The whole light post could be an "i". Chicago has so many architectural elements that you are sure to find lots of interesting shapes and designs if you just look.
There are also many icons to be had such as the Chicago Theatre sign. Forget spelling the letters out....just use the sign already with it spelled out! There are also cool signs at the visitor signs that can work as an introductory photo for a photo album or book created on line.
WGN, the famous Chicago station! I saw things on this trip that I had never seen before like the very cool aspect of the Tribune Tower, where they have rocks and pieces from famous buildings and locations from all over the world embedded in the stones of the tower with the item description engraved next to it. I also had never spent much time on the river walk, or ridden a boat or the Ferris wheel....so much to share!