Are Lies Morally Wrong?

I think there are certain instances where lying is alright.

For instance, if you're in danger of crushing someone's spirit, a little white lie is ok.

I believe that you can ruin someone's trust in you, though, so it's much better to tell the truth.

My question for the class:

Have you ever told a lie that jeopardized your relationship with someone? If so (and if you wish to answer), what was their relation to you and do you regret whatever lie you told?