Considering how much I pay every month for cable, I have often thought of doing the same thing. The only reason I haven't cancelled it yet is that I also have my phone and internet. We also have an alarm system that requires a phone line, which the cable provides. We hardly ever use the land line for talking as both of use our cell phones almost exclusively. The only exception is my mother-in-law who lives in Canada. We have a package on our calling plan that includes free Canada calls.
So I guess were keeping the cable.
My internet and landline cost me $57 with AT&T. I don't have unlimited long distance, but I think it's about ten bucks more.