Probably not exactly what you were asking for, but my all time favorite was back when I worked for an ISP, and we had a core router go down in the middle of the night. I get out to the POP and find that in order to get into the console of the router, I need to be able to plug a female 9 pin connector to a female 9 pin connector for the cables that I actually have with me....
I promptly found a couple of paperclips lying around and used my side cutters to cut off several lengths to short between the two connectors and make a gender-changer and Null Modem adapter in one, since it turned out I needed the null modem adapter too...