Push and hold power button, the phone will reboot. Works with phones with removable batteries too.
This is not a universal truth - it may work on your phone, but that does not mean all of them. More importantly, this is a software feature - it's there if the ROM developer put it there - meaning some phones would have it and others wouldn't. But this is the really important bit - unlike a hardware reset,(like the reset button on a PC) a soft reset ONLY works if that piece of code is executed. If the phone is frozen, it may not do it because it's stuck in a loop and never watching the button or the sequence of buttons.
That's why removing the battery works - you reboot the ROM from scratch.
Personally, I don't care about a battery being removable, as long as there is some way of performing a hardware reset. It's possible, but it costs more to implement than simply making the battery removable.Removable batteries ARE going to die, because Li-Po batteries are so much lighter and more powerful than NiMh or Li-Ion. However, LiPo batteries need to be sealed away from the user because they can burn in an extremely dangerous manner if punctured - for all practical purposes, it could be called an explosion. LiPo batteries used by RC modellers have caused house fires, - serious fires that in some cases have completely burned down the house.
My personal needs dictate that unless I can find a phone with a hardware reset, I'll be chasing removable batteries, even if it means I'm not buying the latest technology.
Best Regards,
Richard.