I realize this is a zombie thread so I didn't bother to read the evolution of the thread. But in the case of a high school or even college graduation party, wouldn't the kid's parents be the one throwing/hosting the party? That's a little different than throwing yourself a baby shower where you're essentially telling people to come shower you with gifts.
That said, I do feel for women who have no one throw a baby shower for them. I don't see anything wrong with having a little party to celebrate your baby, but I would not register or openly ask for gifts.