If housekeeping says it's okay to take them, I think it's extremely judgmental to assume they must be lying and only the hotel manager should be asked (like he or she wants to be bothered with something that trivial!) We have a fish towel animal in our home. It had little eyes glued on it, so it was never going to be a washcloth again. It was made from a pretty threadbare washcloth, too.
I never told anybody to ask the hotel manager - of course he/she has better things to do. But if you need an answer - if you need to take them and you need to know that it isn't stealing, then the manager is probably the only person with the authority to answer that question.
Let me ask this - if a maid told you it was OK to take a regular towel home with you, would you believe that it was OK because the maid said so? What if she said you could take the pillows home with you - would that be OK? The answer is 'no' because the maid doesn't have the authority to tell you to take the pillows and a reasonable person wouldn't believe the maid had the authority to tell you to take the pillows. No, you wouldn't have to ask Michael Eisner because it is reasonable to believe that a hotel manager would have the authority to tell you to take them, even though they aren't actually his.
Yes, this is a ridiculous thread. But as long as we're interested in our little debate, why should anybody care if the issue is insignificant? I'd say that's getting a bit judgemental . . .