First off. Have a look at image hosting sites. Look at what ads they display, that's how they make their money. Usually its through email submits and legit ppi's like zwinkys. Photobucket is a good example. They also make money through paid upgrades.
I think most of them have CPM ads, I'm finding some good image hosting script that allow me to provide paid upgrade, too
First, a free image hosting script -> mihalism multi image script Second - some CPM ad companies which let You earn from Your image hosting - > List of CPM Companies Add a good, stable hosting + some luck and you have a little earning machine
FREE IMAGES HOSTING <--- like this ? You should to build a website and introduce it to people . When they use it to daily service they need. You can get very much visitor and pageview. From that, you can register Google Adsense to make money or you can promote product related with your website such as online storage or etc ... Make sure you website is good before you want to make money !!!