I.C.U.P.

I tried Skype-ing with my sister and her kids the other day from my cell phone while I was on lunch at work, but I couldn't get it to work.  We tried several times, but just couldn't make it happen.  This perplexed me.  So, later that evening, while I was getting ready for bed, I started messing with my phone.  I sat down on the toilet (no, I wasn't going on the toilet) and tried Skype-ing Clinton.  To my surprise (and his) it worked!
He:  Are you calling me from the toilet?
Me:  I'm sitting on it.
He:  Is this what people mean when they say "nature calls"?
Me:  (Laughing)  Where do you come up with this stuff?