I had an original iPhone (4GB) for the better part of a year until I decided to play (iPhone) God and attempt to perform a motherboard swap with an 8GB version. To make a long story short the 8GB version was dead already and I already opened my own iPhone up a number of times on previous occasions for miscellaneous reasons.
If you ever held an iPhone you could probably tell that it wasn't meant to be disassembled, let alone half a dozen times. Well eventually, the last time I tried to put it back together again it failed to power up again. I killed it.
I was forced to fall back to my humble and trusty Motorola V3 RAZR for a few months. I probably could have used the RAZR indefinitely. However the battery on the RAZR was losing its edge and the need to be charged every day had started to annoy me. This Friday the 13th I finally had enough and decided that it was time for a new iPhone.