when it first started i went for 118 188 (obvs) till i realised its about £8.50 a min to call them.
i always go for 118 500 now. to me it sounds like they say, "118 BT direct enquires, whats your name please?" when they answer, but i'm sure i'm wrong.
one of the old buildings on bishopsgate (no, 118) has 118 118 written above its door, which made me laught this morning.