Multiple tagged images

I would like to be able to post images and tag them with multiple categories so that they can be present in multiple galleries. For example:

My friend and I are both authors of one blog. I uploaded a picture of my friend and I surfing. I would want to tag this picture so that it shows up in my main picture gallery, his main picture gallery, my surfing pics, his surfing pics, my vacation pics, etc…

WordPress deals with regular posts this way, but every plugin I have found does not have this option. I am looking for a non-hierarchical way to tag an image with multiple tags so that it is shown in multiple galleries. I am somewhat of a newbie and any help would be most appreciated.