ClubSNAP doesn't provide space for members to upload their photos, unless you subscribe to their hosting plans. Even then so, it's only a web space and the forum has no option to directly upload photos to the web space.
Most free sites don't provide a "direct link", meaning that the pics won't show up even if you used the tags to link the pictures. You can only provide a link for people to click on.
As for which free site to use, I'll let other people help you.