In a new post to his blog Paul Jones points to an older post from The Register that PHP is more like a handgun (than a "ball of nails"). As Paul quotes:

PHP is like a handgun. On its own, it is simply an inanimate tool that has no moral leaning. In the hands of a responsible citizen, it can be used to the benefit of society. But in the hands of someone who is untrained or mentally unstable, it can be used to commit horrible atrocities.

The article (originally published in May of 2009) was specifically looking at Microsoft's choice to include PHP support in their Windows Azure hosting environment and ho, despite their best efforts, Microsoft is still not doing it quite right when it comes to Open Source.