This my current cell phone:

bigger
It is an Ericsson T39M bought in 2001. I have used it since. Back then it was the top-of-the-line phone and cost, in today's equivalent, some €600-700 ($800). It has triband GMS which enabled me to use it in Europe and in the United States. GPRS and HSCSD allowed for fast 56 kbit/sec data transfers. I had also bought the wireless Bluetooth headset for the phone but soon lost it. It was anyway somewhat unpractical.
Despite daily use and rough handling the phone itself shows no sign of aging. (The light color of the phone attracts lots of dirt and I did not clean it before taking the picture.) It works very well. The rubber cable coating of the charger has fallen apart which necessitated a support construction, made from matches and tape, at the connector side.
I would love to keep the phone for another 17 years but its battery is dying on me. Originally the phone would be up for three or more days under normal use. It is now down to less than a work-day. Talk time is down to some unpredictable 3-7 minutes without recharging. This is no longer acceptable. 'New' special batteries for this phone are offered on eBay and elsewhere for €50 to €80. But their provenience is murky and the only dealers are in Turkey, Serbia, Hongkong or Indonesia.
The obvious question came up: Should I buy a smartphone to replace my trusted Ericsson?
I tested several of the current top-of-the-line smartphones – Motorola, Samsung, Apple. They were in the same relative price range as my old Ericsson was at its time. But they lack in usability. They either have a too small screen for their multitude of functions or they are bricks that require an extra pocket.
In 1999 science fiction writer David Gerrold was asked how cell phones would develop. He correctly predicted the integration of all media, communication and services into one 'smart' device:

via Esther Schindler – read the full column
But Gerrold was wrong with this part:
It will be a box less than an inch thick and smaller than a deck of cards. (The size will be determined by the convenience to hold, not by the technology inside.)
Progress in the mobile phone market was once defined as phones getting smaller and thus easier to carry. But all the new phones are larger than my old one. Why did this happen?
This graphic offers an explanation:

The arrow points to the moment "where people discovered
via Carl Zha – bigger
I don't watch porn. But if I would watch porn I would want a screen big enough to see the details. Any handheld device is too small for that.
Most people I observe use their smartphones for "social network" stuff. To them smartphones are a synonym for Facebook, Whatsapp and other such services.
I don't use social networks. The one Twitter account I have is exclusively used for writing and promoting this blog.
Smartphones and the attached social networks make you dumb – literally:
The results of experiment 1 indicate that the mere presence of participants’ own smartphones impaired their performance on tasks that are sensitive to the availability of limited-capacity attentional resources.
…
… the results of experiment 2 suggest that the mere presence of consumers’ own smartphones may adversely affect cognitive functioning even when consumers are not consciously attending to them. Experiment 2 also provides evidence that these cognitive costs are moderated by individual differences in dependence on these devices. Ironically, the more consumers depend on their smartphones, the more they seem to suffer from their presence—or, more optimistically, the more they may stand to benefit from their absence.
Smartphones take up A LOT of time:
[A]n average smartphone user clicks, taps and swipes 2,617 times (145 minutes) per day! With heavy users that number jumps to 5,427 times (225 minutes) per day.
Another disadvantage of smartphones is enormous amount of personal data they inevitably steal for uncontrolled use by third parties. The technical consultant Dylan Curran studied this:
Want to freak yourself out? I'm gonna show just how much of your information the likes of Facebook and Google store about you without you even realising it —>
As soon as an Android smartphone is switched on Google will collect ALL data on every location change and on anything done on the phone. Apple does likewise with its iPhones.
Most applications on a smartphone will collect and sell not only your personal data but also of those persons you are in touch with. As soon as you install Whatsapp ALL personal contact data of other people stored in your phone-directory is transferred to Whatapp's servers. Under German law it is illegal to do this unless everyone in your phone book explicitly consented to it.
Any mobile phone can be tracked by the telecommunication provider it is connected to. We usually know and trust these providers. They are regulated. But a smartphone positions can be independently tracked by various third parties even when its location service is turned off:
We describe PinMe, a novel user-location mechanism that exploits non-sensory/sensory data stored on the smartphone, e.g., the environment’s air pressure, along with publicly-available auxiliary information, e.g., elevation maps, to estimate the user’s location when all location services, e.g., GPS, are turned off.
In his 1999 prediction David Gerrold acknowledged the inherent danger to privacy 'smart' integrated devices would create:
I call this device a Personal Information Telecommunications Agents, or Pita for short. The acronym also can stand for Pain In The Ass, which it is likely to be, because having all that connectivity is going to destroy what's left of everyone's privacy.
I do not want to give all my data into the hands of some unaccountable billionaires and unknown third parties. I do not want my privacy destroyed.
So no – I decided not to buy a smartphone as replacement for my trusted Ericsson companion.
Here is my new phone:

bigger
It is a Chinese product sold in Germany under the Olympia brand. It is a GSM quad-band 'dumb' phone with FM radio and a flashlight. The standby time is 140 hours and talk-time is 3+ hours. The battery is a standardized model and future replacements will be easy to find.
Size and weight are nearly the same as the old Ericsson. The keys are much bigger, illuminated and easier to handle, especially in the dark. It is a robust construction and the sound quality is good.
It cost me €22.00 ($26.40).