How do I encourage site visitors to comment and vote?

So my site has been up for awhile now, and I'm getting lots of hits and downloads but nobody seems to be commenting or rating (voting) on any images. I did that on some of my images and there is a direct menu link for "Top Rated" and "Image Comments", but mine are the only ones there.

How do I put a message in the header that reminds site visitors that they can rate and comment on any image?

I created a new Article which shows at the top of each menu item. For example, I created a Top Rated menu item and associated it with an article called "Top Rated". Then I added a new module and called it "Top Rated" and gave it the parameters I wanted to show. It's kind of a sneaky way of doing what I want it to do, but it works like a charm, but have only had it up for about 4 hours. I'll have to wait for people to read the article at the top of the page to see if anyone understands that they can rate and comment on each image.