[jessedhillon]

What about lying or simply not answering?

Why would an interviewer have a right to know your current salary? That person is tasked with acquiring your intellectual resources at the lowest price possible. And by giving them your current salary, you're clearing up a big unknown in their equation -- your current alternative to a negotiated agreement.

When you go and buy a car, the sales people don't generally offer to tell you the car's invoice price, do they?