If you have to state salary requirements, say "My salary requirements are negotiable."
Hold them off for as long as possible, and make them throw the first number out there. If pressed, ask them if they could give you what they feel is an acceptable range for the position.
(This happened to me in a recent salary negotiation. Luckily, I was able to make them say the first number, which - shockingly - happened to be about $10K above what I expected.) Your starting salary will rarely be higher than the first number you say, for obvious reasons.