Is there a way to have strangers tag my images? I would have liked to know what thoughts people get from various images, so that I could trigger targeted thought patterns with images.  

An easy way to do this would be if I could find an online service that lets strangers "tag" my images with their own keywords. Especially if I could somehow count votes for each keyword/tag.

Does there exist any kind of service like this?
Or does anyone know of a similar approach I could use?
Amazon Mechanical Turk is perfect for something like this.  In fact, tagging content is one of their default project types, so you should be able to just load in your images and use their template for tagging.

If you haven't seen it before, MTurk is basically a labor marketplace for very small tasks. It works best for paying people a few cents to complete very short tasks, but it is frequently used to recruit subjects for longer behavioral studies as well.