We prove sharp Lp(w) norm inequalities for the intrinsic square function
(introduced recently by M. Wilson) in terms of the Ap characteristic of w
for all 1<p<∞. This implies the same sharp inequalities for the
classical Lusin area integral S(f), the Littlewood-Paley g-function, and
their continuous analogs Sψ and gψ. Also, as a corollary, we
obtain sharp weighted inequalities for any convolution Calder\'on-Zygmund
operator for all 1<p≤3/2 and 3≤p<∞, and for its maximal
truncations for 3≤p<∞