Cell phones can be useful, interesting, and entertaining tools, but sometimes they are less useful than they are annoying, or even harmful, to relationships.
I use my cell phone quite often, but one rule I have for myself is to use it as little as possible when I'm hanging out with friends or family. There is nothing more frustrating to me than when I'm talking to somebody and they pull out their phone and start texting as I'm speaking, or when I try to talk to a friend and they are more interested in their phone than even listening to what I'm trying to say.
It baffles me that pulling out a phone during conversation is considered normal behavior, when to me it just seems rude and disrespectful. A friend I had in high school could barely hold a conversation with me without using his phone for something unrelated to the conversation. I can see a phone being useful for looking up a subject mentioned in a conversation, but even then, if it's a one-on-one conversation, it makes more sense to just ask the person speaking more about it than looking it up in the midst of them speaking.
I didn't even own a cell phone until my senior year of high school - and I survived fine without one. I never needed a phone for anything I did in my daily life, and it seemed crazy to me that people seemed so addicted to their cell phones. Now, I can see where they come from and how tempting it can be, but conversations still hold my attention more than whatever is on my phone. I rarely actually laugh out loud at something I see on my phone, but laughing during the conversations I have with my friends is common. I still don't understand why people prefer smirking at their phones than actually laughing in a face-to-face conversation.
Neither my long-distance fiancé nor I had a cell phone the first few times we met in person. Instead of sitting on our phones when we weren't out doing things, we talked - and those times are some of my favorite memories. I don't have any memorable times when we were together and on our phones, but conversations we've had and laughs we've shared are quite prominent in my memory.
The same goes for being with my friends, and I'd rather make new memories than have the fleeting entertainment of an hour of browsing Reddit or Facebook. I'd also prefer to not make my friends feel like I'm disrespecting them by ignoring them for an inanimate object.
Personally, I get a bit offended if somebody pulls out their phone and uses it the entire time somebody is speaking. I don't mind as much if it's a few short times, or if it's used to contribute information to a conversation, but otherwise the disrespect pushes me away from that person.
If I can't talk to somebody and have them listen and speak back, what is the point of the friendship? What's the point of hanging out with a person when I'll just end up on my phone as well to avoid the awkwardness of conversation with myself? What's the point of a person hanging out with others when they could do the same thing alone and not feel any different? Phones can be used to provide social interaction through messages, but they should not be a permanent part of an in-person social interaction.