How to deal with a friend who won't stop talking and calling! I'm at the end of my rope of patience!?

I've known my friend for 15 years, we live in separate states now. Our friendship has waxed and waned in closeness over the years, but lately she's been calling EVERYday. She goes on and on about trivial things and going into endless detail about simple tasks. I've tried listening, commenting on her activities and stories, asking questions, saying nothing, mono-syllable answers, changing the subject, trying to get in a word edgewise about my life, and flat out not answering her calls for a few days. All to no avail! I make an effort to keep the monotonous details in my life out of our conversations, so I'm tired of being the one she calls just to fill the time. I need my space! I do want to keep her as a friend, I would just like our relationship to be less "clingy". I'm uncomfortable with being "%itchy" about her chatter so am I encouraging this behavior? Is she only talking to fill the void in conversation? Any phrases that would help change our style of conversation so I don't have to be the one always dashing off the phone to prevent another detailed catalouge of her day?