Is Lying Always Wrong?

Consider the following; the body of a young British soldier washes up on the shores of mainland Europe. It is seized by the Nazi's, and on the corpse is found vital strategic information that can be used against the enemy. Only later does it emerge that the body was not in fact that of a soldier, but simply that of a person whom has died of natural causes and then used by British intelligence to spread disinformation in order to spread a strategic advantage. 
Scenario two; a desperate female, battered and bloodied awakens a sleeping couple and pleads for sanctuary, her abusive husband having deployed his full drunken rage upon her only minutes before. She is given safe haven, and shortly after the male presents at the door and, dripping with sweat and rage, demands to know whether the couple have seen a runaway girl? The couple stare blankly at him and deny any such sighting, at which point the male lumbers away into the night.
Two images, two snapshots. You've identified the theme already, haven't you? What I'm suggesting is that as much as we find it distasteful, there will be times when lying is absolutely the right thing to do. Perhaps you find this unsettling? If so you're in good company. I like to know who I'm dealing with, and trust is massively important to me, yet as I reflect on these examples and others I am forced to admit that there are times when brute honesty just isn't going to cut the mustard?
Why am I blogging on this? I've been in dialogue with an American evangelical, and they made a statement to the contrary. I couldn't help but seize upon this, as it once more serves to illustrate the naivety of some world views. Like it or not we live in a complicated world, an unsettling world, and in order to cope with this we've evolved codes of conduct and moral behavior that generally stand us in good stead. They help us in our interactions, and have enabled us to forge a society which whilst imperfect, is a considerable improvement over the world our ancestors inhabited. Yet there exists a subset of society, invariably believers, who insist that there exists an absolute morality that should somehow be considered the benchmark, the plumb line, the ground of all morality. They of course cite God as ideal for this role, and argue that without an external moral agent there is no means for us to know right from wrong, and that refusal to admit this is simply to say that we're just dancing to our DNA.
This to me has always seemed odd. Child like, even. These appear to be the musings of minds trapped inside the prison of religious certainty, subject as it is to the law of diminishing returns. When I consider moral issues it seems evident that shades of grey proliferate. For the most part, honesty and trustworthiness are admirable and appropriate modes of conduct which help society's to remain on an even keel, yet as we've seen we dare not be so credulous as to adopt a one size fits all approach. In doing this we make ourselves blind to the complexities of this life, and by being so fixed in our views we can expose others to great harm. Happily, most of us are free from the dogmatic enclave of religious delusion and are able to think freely. This to me is really important because the world is facing challenges now that are going to require every fibre of imagination and endeavor we can muster. So let's tackle these issues with emotional honesty, let's admit that the world sometimes throws up the odd anomaly or two, and let's see whether approaching complex issues with a supple mind get's us any further down the road.