galaxy3 update that keeps updating for 3 days plus! My Galaxy 3 said there was an update to 4.3 available. So I connected a charger and started the upgrade. It warned me that I cannot use phone while upgrading, even for an emergency, bla bla. Of course, I continued with the upgrade, and it went through a couple of processes and then said android is now rebooting! 

After it reboot, it came back on saying was upgrading my apps. 

That was 3 days ago and is still saying it. I've taken the battery out, put it in, switched it off then on, etc. As I'm typing this, it's still saying the same thing! I can't do a thing with it now!

Any ideas to what is going on? Or is my phone now rendered useless?
It is unlikely that your phone is useless. From the symptoms you state, it sounds like you have done one or more of the following,


Rooted your phone
Unlocked the bootloader
Installed a custom recovery
Installed a custom ROM


If even any one of these is true, the OTA update will fail and redownload itself because it thinks it was a bad package download.