legend: bold and color of border

How do I write bold face in the legend - the function does not accept
font=2 as argument?

How do I plot a legend box with a background color, but not a border?
Or, better: How do I specify the color of the legend-box-borderline?

Okay, I abuse the legend, but have a look at
http://de.wikipedia.org/wiki/Bild:EurUsd.png if you want... Any
help/feedback appreciated!
Thomas