Wikipedia is pretty good. There's been some discussion that it is sometimes as accurate as the Encyclopedia Brittannica. (Watch out for certain Troll-Prone pages though!)
Yes, Academics around the country (USA) wail about how Encyclopedias are never the end of scholarship, but to settle a basic argument or get the gist of a topic, it's better than wild rumors that circulate otherwise, or simple plain being-totally-lost.
(Without the Internet/Wikipedia as a subset, for twenty years (!) I didn't understand the car jokes in the movie My Cousin Vinnie (from 1992). What Da ____ is "Four Degrees Before Top Dead Center? Oh right: "Timing advance" refers to the number of degrees before top dead center (BTDC) that the spark will ignite the air-fuel mixture in the combustion chamber during the compression stroke. http://en.wikipedia.org/wiki/Ignition_timing)
However, there were a few notorious hoaxes pulled to take Wikipedia down a notch off its high horse.
Ironically, when the story broke, it was all about how great Jimmy Wales was. Except, from *their own history page*, we get this:
Let's try the hoax that Jimmy did it all. The correct answer is:
The earliest known proposal for an online encyclopedia was made by Rick Gates in 1993, but the concept of an open source web-based online encyclopedia was proposed a little later by Richard Stallman around 1999.
Wikipedia was formally launched on 15 January 2001 by Jimmy Wales and Larry Sanger using the concept and technology of a wiki pioneered by Ward Cunningham.
What happened to Larry Sanger so that he does not even get mentioned anymore?
One of the long-running but topical discussions is the Deletionist situation. One viewpoint, bunratty from Slashdot:
"...People tend to forget that it's an encyclopedia, not a place to deposit the sum total of all human knowledge on every subject. Encyclopedia articles should cover only the most important aspects of a subject. Readers who want every little detail should go to the sources or other material referred to in the article..."
So Wikipedia is definitely not quite the "free-of-peer-pressure" exchange of ideas. There's definitely an art to getting a fact to stick.