Matters are not helped when psychologists cannot even agree on an operational definition of intelligence. As I understand it the most popular definition is "the aggregate or global capacity of the individual to act purposefully, to think rationally, and to deal effectively with his environment," which comes from Weschler (the Weschler Adult Intelligence Scale is what most people are talking about when they say "IQ test") With that said, my FAVORITE definition is "Intelligence is what intelligence tests measure."
Separating the formal conception of intelligence from what society commonly understands to be intelligence can be difficult and lead to a great deal of confusion. Having a vast store of knowledge that you have memorized is something that would make people say "wow you're smart", but has no relation to the theoretical construct that intelligence tests are trying to measure. As you note here, there are also multiple kinds of intelligence as identified by various people, and intelligence in one category does not reliably predict it in others (some may be related, although separating them into discreet things which cannot predict each other was the whole point of having a theory of multiple intelligences).
I would suggest that internet posts are a very poor way of metering intelligence, at least in the formal context, since we are so rarely given an opportunity to display anything other than knowledge.
