Your dad was #1002?
MY dad was #1002!
Oh my god... you're my half sister!
Eeeeewwwwwwwwwww.
No need to wait a few years, because according to the article:
"Through the Donor Sibling Registry Web site, [Liz] has discovered at least 10 half-sibling and has met seven, including Callie from Pennsylvania.
"Liz's mother, Diana, thinks these newly forged relationships will last a lifetime."
They're will need to carry a DNA signature with them so they can compare and weed out half-siblings. New use for cell phones, I guess (you saw it here first - recorded for posterity).