My iPhone is almost full of photos, which is no small part due to the fact that I have a 7 month old boy and we've taken about a thousand pictures at this point. When Apple starting offering iTunes Match, enabling you to take all of your music off your phone and stream it from the cloud, I was ecstatic. Why haven't they offered something like this for your photos? Well fear note because thanks to an app called CameraSync, some good things are now possible.
CameraSync has been around for a while and it basically just allows you backup your camera roll to cloud services like Dropbox or even a FTP server. That still required you going to the app and opening it and then leaving it open while ALL of your photos were backed up to the server. They just updated the program last week so now you can set certain locations by GPS like your home or office where the app will automatically start running in the background and upload all of your new pictures. I've been using it for a few days and it is seamless. I highly recommend it.
Once the photos are uploaded you can delete them from your phone and use the Dropbox app to stream your photos. A near perfect solution.