Like most things that are popular in the modern world, cell phones and other handheld devices have both admirable and abominable qualities. On the one hand:
Cell phones! Cell phones are awesome. They’re like the “communicators” that Captain Kirk used to talk to other crewmembers when he and his buddies had beamed down to some alien world with the sky painted onto the background 15 feet away.
Star Trek takes place like 300 years from now, and yet we have that same communication technology now. Not to mention, Captain Kirk's communicator had just that one ring-tone, whereas we have lots of options to alert us to an incoming call: anything from the classic sound of an old analog telephone to the nasal bleating of the music of Rihanna. Cell phones! Awesome.
On the other hand:
I'm not going to go on about phones ringing at the movies, mainly because there are far worse things in movie theaters, like paying $14 to see a movie and then having to sit through Coke commercials. However, whether in a theater where you're eating $9-worth of stale popcorn, or outside in the light of day, even the way a cell phone rings is inherently annoying. Let's compare: when there's an incoming call, an old-timey land-line phone leaves you with a few seconds of silence between each ring. This allows you to think clearly and decide if you want to answer it or just go back to darning your bloomers, or whatever it is that people who still rely on land-lines do when they're at home. A ringing cell phone, though, is like a whining little baby that never comes up for air.
I suspect that cell phone companies deliberately planned this to add a sense of dire urgency to every call, especially considering that when cell phones first arrived you were paying through the nose for every minute you used it. When you hear the insistent ringing of a cell phone, subconsciously you sense that whatever info is going to be related is certainly more important than repairing your bloomers, washing your hair, or ironing your poodle skirts.
Of course, if your cell phone has a ring-tone of the aforementioned "music of Rihanna," then its whining isn't so much insistent as it is ruminant:
Music to your ears, or just irritating? Cell phones! Awesome.