I need to get out of a bad situation at my current work - I like the work, but they've been jerking me around with contract extensions coming at the last minute. I've been offered a job at a different company that doesn't look as interesting, but it's a chance to learn a few technologies I was interested in learning. It's "6 months contract to permanent" - does that mean that if I decide it's hopelessly boring and quit after the 6 month contract period that it won't reflect too badly on me and ruin my reputation in the town? What if I quit earlier than that?

Edit I should mention that I don't think there will be one right answer, so rather than accepting one answer, I'm going to vote up the good ones.