So I thought the photos I take on my iPhone 4s are suppose to sync to my Mac/iCloud? I don't see this happening. Am I not looking in the right place? Do I need to upgrade my iPhoto?
In order for your Mac to use iCloud (and therefore give iPhoto access to Photostream), it has to be running OS 10.7 (Lion). As I mentioned before, you also have to have the latest iPhoto.
Once you have that installed, you will see a "Photostream" entry in the left-hand pane of iPhoto where you will see all of your photostream photos.