Should I just tell him how I really feel about him?

I have a friend who I met last year. I know he obviously wants to be more than just friends when he leaves me messages such as "I want to see you, I need to see you". Anyway the thing is he is really boring and when I went to the movies with him, I was bored out of my life. We have zero chemistry and I don't even know why he's still trying to pursue a relationship with me when we obviously have no spark between us. It'll never work between him and I. He doesn't know that I don't want a relationship with him though. I'm not leading him on or anything but I'm really friendly to him and he takes my friendliness as a sign that I want him ( which I don't). I'm the type of person that's afraid to hurt anyone's feeling but its getting really overbearing when I feel obliged to call him to say hello and endure the long boring minutes on the phone with him.

Do you think I should just be blunt and tell him "I'm just not that into you" or should I just grin and bear it to spare his feelings?