Most things seem older than they actually are to me. This seems like it's been longer. I can't believe it's was less than 15 years ago when I was first playing with custom roms and overclocking my android phone.
My first smartphone was the Motorola Droid 2 and it could easily be over clocked from 600 MHz to 1200 MHz. The dynamic overclocking even helped the battery life. I miss the keyboard, it was great for playing old video games on emulators.
My first was a Samsung Moment slider phone. I still miss having a real keyboard.
It was an 800mhz arm11 chip. I think I was stable at 1100, but can't remember for certain anymore.
I know I could do a lot of custom charge settings and stop it from charging at whatever percentage I wanted it to stop at. Something you STILL can't do on most phones, but should be able to. A lot of phones now at least give you an option to stop at around 85% by enabling "battery saver", but what if I want it to stop at 90% instead?
Those early smartphone designs were really something else. I think they were trying to make it look like space ship controls, but it just ended up looking like a car stereo.