I've got two....
First happened last November at this gigantic industry trade show in NYC. I was manning a recruiting booth for the career fair section, and a gaggle of GORGEOUS southern girls comes waltzing over and begins to ask about my company, what we do, etc. Knowing that they are college age, I ask where they are from and find out they are from ECU - one of the few NC schools with a APhi chapter. I casually ask if they are in a sorority, and sure enough the entire group are Phis!!
Second one happened this past summer at my best friend's law school graduation...she had two of her college friends there who I had never met, but were a ton of fun to talk to and just great gals. We start chatting some during the graduation reception, and one of the girls says that she was in a sorority - when I ask which one, turns out both girls are Alpha Phis!
Both encounters ended with the obligatory gigantic smiles and "oh my god so am I!" screams...yes, at the trade show half of my colleagues thought I was nuts.