I got one of these a couple weeks back. Really works great. http://www.adorama.com/DKEB1620.html in expensive too.
Put the negative in the stage, use the back of a trash sheet of paper to set up your paper position, slide a magnet up to one side of the trash sheet then one on top or bottom, remove trash sheet.
When ready to print slide the fresh sheet of paper up to the magnets then remove the magnets, prints perfect borderless.