Watch the Bends & Vibrato Exercise 2 online guitar lesson by Jeff McErlain from Beginner Blues-Rock Soloing
One of my favorite players that utilizes the half-step bend is David Gilmour from Pink Floyd. It's an integral part of his playing as it allows him to finesse the note for a really nice emotional interpretation. A solo that sticks out to me which uses the half-step bend is his solo in "Mother" from The Wall. I highly recommend checking out one of his "simpler" solos like the first one in "Comfortably Numb" as well.