Astronauts have been known to be up to 3 inches taller after return to Earth from space but their spine will compress back to normal length after gravity takes effect. The tallness would disappear probably after a day or two! The 0-g environment allows your spine to decompress. This is because there is no weight that your spine has to bear.
Also, it is a known fact that when you wake up in the morning your height will be millimeters taller than your height at the end of the day. This is because during sleep your spine isn't bearing as much weight as when you are standing on two feet.
If you hang upside down for a long enough time, it would in-fact increase your height. But this height change would be minimal an last no more than the time spent upside down on the bar! Also you would most likely red-out or pass out before you would get taller.