Checking out at a grocery store to which I rarely go, the cashier asks me if I want an Albertson's card. I respond sure and she hands me the form on which I give up my personal information. I ask if I need to fill this out now, and she says yeah and it will only take two minutes, which surprised me because at QFC they just hand me a new card and send me on my way. I fill in my phone number as the first ten digits of pi so I don't have to worry about getting phone calls but its something I can remember next time I'm there and don't bring the card.
I turn to leave and the cashier asks me is that a '759' or '159' in my phone number. I stop for a second because I only know the digits as a sequence from the start and pause long enough reciting it in my head that its clear its not my phone number. And she calls me out on it: "Is that your real phone number?" I sigh, "No, does it have to be? Are you going to call me?" "Yeah," she says, "I'll call you." (ha ha) "Well I'll try entering this number," she says doubting the computer will accept the fake phone number. "On the number's already registered," she says, "So you already had a card." "No," says the manager who had walked up during for this exchange, "It means someone else used that same number." So the moral of the story is, try your fake phone number before trying to use it to get a new card.