Interview tomorrow. What's your strategy for this question?

[C.R.E.A.M.]

I've got a job interview coming up this week. I consider myself fairly adept at handling interviews, for the most part. The one question I'm never sure how to handle though, is when they ask you about your weaknesses. It's usually something like "what do you think are your weaknesses" or "if we spoke to your last employer, what areas would they say are your weakest".

What do you think is the best way to tackle this question?