Cell phones are
a) a source of batala and terrible images
b) a disruptive influence that should be avoided by serious yeshiva bochurim
c) problematic, but the good outweighs the bad
d) really fine, but I understand the concerns
e) just cell phones. I don't even understand why this is a question
f) Leave this question out of my results
I chose (d). I understand concerns with cell phones; I've seen people waste copious amounts of time with them, and I'm sure that people can do even more dastardly things with them, if they are so inclined and lack sufficient self-control. See what I wrote about #18 (television and movies) and #19 (the internet). The same applies here, except that I would classify a cell phone as a tool, rather than a medium. This distinction, however, is irrelevant. Just as one can use a hammer to build a sukkah or to smash annoying people over the head, so too cell phones can be put both to permissible, even desirable, and to forbidden uses. The tool itself is not intrinsically good or evil; one must ensure that one employs it, like any other tool, properly.