How great would it be if after years of being accused of ripping off everything from Batman, Green Arrow learned that Batman's greatest ideas were modifications of existing tech from earlier heroes?
I do remember the Batarang attached to the Bat-line, most vividly from the 60s series. I seem to remember a cover during No Man's Land that had Batman throwing a Bat-line out, but that's the last time I recall it. And in all honesty, Batarangs don't necessarily show up that often anymore either.