The answer I've always heard (I don't know who thought of it, but I like it):
The "E" in SAGE is the missing "E" from the creat() system call.
I've given that answer several times, usually well recieved. I once did
a PGP information session on campus, which many non-Unix people attended
(of course I was wearing my SAGE T-shirt). They didn't get it.
--david