Aha - a simple and clever way of putting posters up. :D Good idea Junkaholique!
DIY magnetic Hanging Poster Frame from curbly.com
How to Hang a Tapestry in a Dorm Room using Command Strips and clothes pins (video demonstrating it). This can be done to hang posters, pendants, and pictures too.
Maple Hanging Poster Frames by Ferm Living More
Beautiful DIY Poster Frame - I could do this with my turkey fabric!
DIY Hanging Half Frame Tutorial via Design Sponge