Okay, I have to admit that this was my first encounter with the term "black hole", c. 1964. In the story I read a mini black hole (MBH) somehow made it to Earth was was devouring ... Montana? ... and there were fears that it would eventually swallow the whole (not "hole") world. There were various schemes proposed to deal with it, but one guy came forward and said he'd solve the problem for free if he could be granted sole ownership of the thing and any benefits accrued from it. The powers that be gave him the rights based on performance and he spent a lot of money encapsulating it, preventing further erosion of the planet. So how did this benefit him financially? The last scene in the story had scientists and industry lining up to attach their devices to the containment unit. When the right valves were opened the air was sucked out of the machines and a practically perfect vacuum was produced. Apparently there was quite a line waiting their turn. So, what's your favorite "creative" use of black holes in scifi stories?