I've been having a good time with "You and We", a project from Born Magazine that invites you to "contribute your words and images to this continuously evolving, collective experiment." Users upload art, text and photos to be collaged together in a fast-moving montage that actually turns out to be pretty nice. So far there have been over a thousand contributors. [Flash, Sound (toggles), and possibly NSFW.]
Smithsonian Magazine is holding its first-ever photo contest, open to all adult non-professional photographers to submit entries in five categories. (Professionals may want to see about freelance opportunities here.) I find it particularly nice that there is no entry fee, and no citizenship requirements. For inspiration you may want to browse a gallery of Smithsonian freelance photographers or view the beautiful (and seasonally appropriate) Ghost Towns by Night Light and pick up a few tips on night photography from the photographer.
Morbid Outlook is a polished, eclectic Goth magazine with a killer design and content to die for. With hundreds of articles and images in the categories of Art, Music, Fashion, Lifestyle, Fiction and Nonfiction, this is one of the very best online zines I've seen yet. Go to any feature, and you will find a list of related-interest articles accompanying the story, and, usually, a listing of online resources or suggestions for reading as well.