I'm over 50 and I use FB. Like any good tool it's pretty flexible, I use mine for three things. One, as many of the people I work with are scattered to the wild winds most of the time we can all keep in touch with each other. Pretty much everyday I'm in contact with people in Asia, South America and Europe, not to mention all over the US and we can keep up with each other, and the biz. Most of that is 'inside baseball' stuff that only we are interested in. Two, there are a bunch of my friends, people I used to trade tapes with and such, and were constantly posting videos at each other. I don't need to make anymore Grateful Dead tapes because the Dead FB sends out a different set every couple of days. On Sundays we do Jazz Bruch and we all post all this cool jazz stuff for example. Three, family, its a way to keep in constant touch with my kids. None of the people on my list post stuff like "I'm going shopping". A lot of us post news and political stuff and it becomes an outlet for our constant jokes.
I will say this, I only 'friend' people who I know IRL, real friends, not other people who read stuff I post and like it. I have to know you personally, and really like you. That keeps the list down for obvious reasons.
I don't have to send pictures out to everyone, I just post them, works for me. It's a real quick and easy way to share. And the pictures of me on the net are things like me holding Phil Lesh's old Alembic bass, nothing embarrassing or bad, or illegal.
Cell phone? I haven't had a land line in over a decade now. Wires on a phone? How quaint, isn't that the way they did it in the 19th Century? Why yes, they did.