Phone keeps turning off iPhone 4S

I've had my Iphone 4s for about four months now.  Since day one it has turned off at random times, forcing me to do a "hard start" or hold the button + the power button for 10+ seconds for it to turn back on.

Most of the time it seems to be when the phone is in my pocket, but there have been times when it is either on the charger, or sitting on the counter/desk that it's turned off, so I'm not sold that it's a heat thing. 

This has been the most unreliable device I've had (and I had an Eris - if that tells you anything).  When it works it's a marvelous device, but sadly it's not working 5% of the time. 

It's extremely frustrating to make a call only to have to boot your phone.  If I'm driving it's especially difficult because it won't sync up with the bluetooth in the vehicle for several minutes.

I've done some extensive research (yea right) with the help of Google and it seems like I'm not the only one having this problem.  What I wasn't able to find on Google was a fool proof way to make this phone a reliable tool that I can continue to use for flying, business and personal ventures alike.

Any ideas what I can do?  I'd bring it to the nearest Apple store but since this is so inconsistent I might have to be there for an hour or more before the phone decides to call it quits on it's own.

It's a 16GB model if that matters.