Things come from nothing all of the time in the realm of quantum mechanics (see http://en.wikipedia.org/wiki/Vacuum_energy).
The spontaneous creation of particle pairs is not at all an example of "something from nothing", but simply an illustration of "something from something". Vacuum energy is not nothing. That should be obvious.
A proper understanding of what "nothing" means would prevent misunderstandings such as this from coming up. Nothing is literally, nothing. Non-existence. In other words, by definition, you'll never find it.