I think i started noticing on thursday that it was starting to act a little flakey. It seemed to be having difficulties when i pressed the power button. Occasionally it just wouldn't work. Sometimes it would actually flicker the screen on and off as if i'd pressed the button twice really fast. And once friday night (i think) when i turned the phone on the whole thing slowed to a crawl, though i'm not sure if that problem was related or not.
Then early sunday afternoon, while taking notes on one of the AMV panels, the power button just refused to work at all. I'd powered it off and it just wouldn't come back on again. Because of the nature of the issues i'd been experiencing i was presuming it was a hardware issue with the power button and not some software issue, but i still tried the "take out the battery and put it back in" trick just to see if it helped. It didn't, and then a little later i kicked myself when i remembered that the phone automatically comes out of lock mode if you plug in the USB cable. Now that i'd powered the phone off by removing the battery however that wasn't going to work. =P
When i got home i did a little research, and discovered that the power button crapping out is a relatively common issue. On the one hand that kind of sucks, because if it wasn't such a frequent problem it might not have happened to me, but at least since lots of people have had to deal with the issue and the solutions are well known and easy to find.
So the problem is that the power button was not very well designed. Every time you use it the connection flexes a little, eventually leading to breakage.
There are a lot of "fixes" for this problem. The first and most important is that it turns out that if the phone is off, plug in the USB cable, and then take the battery out and put it back in repeatedly the phone will power on. This worked the very first time i tried it. Then when i needed to do it again later it took several tries. There have been reports that some people have had to repeat the procedure a couple dozen times to get it to work, and the efficacy may depend on the power draw of the USB cable (ie, do you have it plugged into a computer, a car, a wall socket, or what.) I'm not sure if the ability to power on the phone this way is a feature or a bug. As a feature, it seems problematic given the erratic nature of it. As a bug, it just seems really damn weird.
But in any case now that my phone was up and running (or at least limping) again, i looked into how to circumvent the problem in the future. It turns out there are a number of apps designed to get around a non-working power button (again, the benefit of a common problem.) Some of them require root access, which i never got around to activating on my phone. I'm especially interested in the "power on using the trackball" app. However since i didn't want to bother messing around with root on a phone that's got one foot in the grave already i just installed the "Fix Broken Power Button" app from the market place, which doesn't require root access and A: allows you to get out of sleep mode using the volume rocker, and B: provides a widget for putting the phone back into sleep mode.
With that installed it seems to work perfectly well, except of course for the fact that the volume rocker has been acting a little funky for months at least, possibly over a year, and adding this functionality on top of actually adjusting the volume probably won't improve its lifespan.
So my phone is kind of on life-support and i really need to start looking at new phones _now_. Which means i probably can't wait to see what the Motorola X is going to be like =/ So if i want pure Android my options are going to be limited to the Nexus 4, the Galaxy S4, and the HTC One =/