its not that testing Fails but its just that thisis an endless process and at some point someone has to take decision to ship it with the known issues.

yeah i agree with most of the comment above but the most imp skill which i feel any manual tester should possess is the Knowledge of the domain in which he is working(which is ignored most of the time),and a very good analytical skill to test different scenarios.
one shold be very strong in basics to make sure he covers most aspect of any product.

But everything said and done thisis also true that its highly impossible (read as not at all possible ) to have a bug free product.
its an incremental process which helps ppl in having a better understanding and more knowledge of the domin which ensures that there won't be any major problem with the build.

Thanks,
Kunals.