When Lying is Okay

Is it ever okay to lie?  The Ten Commandments (Ex. 20) prohibits lying on one another.  The Bible calls Satan the “father of lies”, and says that God hates lies.   But I am wondering if there are some loopholes.  Is it okay to lie if someone’s life is at stake?  Is it okay to lie when we are facing uncertainty?  Is it okay to lie when the truth is inconvenient?  What about lies by omission?  Where do we draw the line?  More importantly, where does God draw the line?  Are our lines cohesive, or do they take divergent paths?

I am wondering what you think.  I usually don’t ask so many questions in one post, but I am pondering these things right now, and I like to ponder with someone.  It helps.  If you’ve lied recently, what was the reason?  How did you justify it in your mind?  Was it worth it, or did the consequences outweigh the expected gains?