What follows is a small excerpt from the commencement address given by Tom Friedman (the author of the 'The World Is Flat') at the Williams College, MA in 2005.

Btw, the address is titled 'Listen to your heart' and is really worth reading..

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Skepticism is about asking questions, being dubious, being wary, not being gullible, but always being open to being persuaded of a new fact or angle. Cynicism is about already having the answers -- or thinking you do -- answers about a person or an event. The skeptic says, "I don't think that's true; I'm going to check it out." The cynic says: "I know that's not true. It couldn't be. I'm going to slam him."

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So, to summarize it, a skeptic is the one who 'questions with an open mind' whereas a cynic 'opines with a pre-conceived notion'..

While the skeptic is actually in search for better info before he can start believing, the cynic is only there to push his opinions..