Usually not. If cable is a rip off, keep only the essential phone line (no VM or CID--use a $15 answering machine, no call waiting, no LD, etc.), and see if they offer metered service instead of unlimited. Metered service usually gives 60-180 outgoing minutes/mo for a few bucks less.
It's not all that bad to have a home line that you rarely use. Personally, I like to have a home line to supplement my cell phone, because I have two phone numbers that way. When I'm working or otherwise out and about, I don't necessarily want my cell phone ringing with junk calls, so good friends, family, and trusted others get my cell phone number, and everyone else gets my home line, which has an answering machine. Another advantage is that I'm listed in the phone book/information, which has paid off a few times when acquaintances or old friends have successfully contacted me. I also receive the local phone books from the phone company--the REAL white and yellow pages, not those fake all-advertising abominations. Oh, and 911 works properly with instant location information from a land line, which is a good thing should I ever need it. (In case you didn't know, the new E911 location service for cell phones is no replacement because it's unlikely to work indoors--no GPS signal gets through most buildings.)
