The Sphinx

The mysterious Sphinx, poser of the famous question, "What walks on all fours in the morning, two legs at midday, and four legs in the evening?"
On a side note, when I was Art Director at Stone Mountain Productions, a discussion was taking place about how "sphinx" should be pronounced.
A woman was asking why you didn't say "spinks" instead of "sfinks", and a co-worker said because the ph made the f sound. She argued that it didn't make sense, and he countered with, " It's the same reason you don't say "telepone".
Good times, good times.