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Hi, we offer such a platform for surveys, polls and quizzes. Our platforms is primarily used for marketing research so advanced analytics are built in. You can analyze how people responded to your survey, poll or quiz by gender, age, location, language or any combination of these (based on facebook profile data). The platform is Facebook based which helps with the virality a lot. Our company is still small, so each customer is very valuable to us and exceptional service with a personal touch is guaranteed. Oh, and we are launching embeddable quizzes and polls next week.
You can take a look at our 2 minute video tour or mail me at slav [at] sociallyapps.com
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Google Docs can be used for polls and quizzes. Article
Wufoo also does surveys and pools, not quizzes though, and they are a cool startup too.