Creative Commons is a pretty cool idea and actually something I've been thinking about for a while now (though admittedly not nearly in such detail). Essentially the Creative Commons is a set of licenses intended for artists to use to clearly specify which elements of their copyright they wish to enforce. I think it's an interesting idea and I may look into it further when I have a bit more time to spend staring at license agreements.
While I think the icons they provide are very useful for creators to communicate their copyright desires to other people, I'm unsure of how useful such a license would really be if a copyright dispute went to court. Would a judge take the licenses seriously?