One program that does this is called Steganos Security Suite. However, it's not a free program but the good thing is it has many features and not just the one you are looking for. If you are after something less expensive or even free, I would check out download.com for any possible programs.

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Just like computer memory, you are only as fast as your slowest part. As I get older, I'm finding more and more "parts" that are slow.