Is it ever ok to lie?

To me, lying is a means to an end, and hence whether lying is acceptable or not depends on the intended nature of the “end”, whether it is “intended” for the good or for the worse.
For instance, a father consoling his terminally ill daughter would lie and tell her that everything is fine, with the positive intention of giving his daughter hope and will to live, which is, of course, morally acceptable.
On the other hand, a tax accountant lying about a company’s income and revenue statistics to the government with the ill intention of avoiding taxes for personal gain is morally impermissible.
Hence whether lying is acceptable depends very much on the intended end-result.
Another thing that I would like to point out is the relative emphasis on intention rather than consequences. (Of course, this is not to say that consequence does not play a role in the determination of whether lying is wrong.) Since events are always unpredictable, things may turn out with unexpected consequences regardless of the nature of the intention.
For example, the aforementioned daughter may accidentally find out about her father’s lies on her medical condition and hate her father because of it until the second she died. This is obviously a negative and unexpected consequence. However, her father’s lies are still justifiable due to his well-meant intention.
And let’s say, if, the tax accountant’s fraud initiated many company financial reviews and ultimately led to a better, more updated and accurate company accounting system, this does not justify the tax accountant’s actions, this does not make what he did right.