I first heard about the balloon on the Joe and Charlie Big Book tapes. The balloon symbolizes my state of being. If my balloon is completely inflated with ego (my false ideas about myself and how life works), then there is no space for my HP to work in my life. Taking the steps deflates the ego, letting some of the air out of the balloon. Since nature abhors a vacuum, HP rushes in to fill the empty space.
I let the air out of my ego balloon by taking the steps and by living them on a daily basis to the best of my ability. Some of my ego deflat-ers are: asking for help; recognizing the limit of my personal will; seeing the not-so-pretty truth about myself; sharing my most embarrassing secrets; becoming aware of my human flaws and the damage they cause myself and others; overcoming my arrogant isolationism and connecting with others; admitting when I screw up and apologizing as best I can. Left to my own devices there's no way I would do these things. Thank God I have a disease that will kill me if I don't.