Ah, yes, wikipedia. I love it, mainly because I can screw around with everyone on it. I behave, mind you, but it doesn't change the main reason why I love it. Not to mention I love cleaning up information.
The Urban Dead wiki is one where I even pretend to have ownership of a page (Bug Reports) and keep it cleaned up - it's due for an overhaul when I'm done studying, an overhaul I'm looking forward to... *evil grin*
Seriously, though, wikis are the workaholic heaven.
As for wikipedia specifically, I use it to help myself studying. The articles on computer science topics are particularily reliable (comparing them to what I learn shows this, at least), but I've also seen other topics, where the article didn't even make sense to me. I'm in complete agreeance with you, AFGNCAAP - one should be careful.
But equally, I think, trusting one's gut is something that should not only be tolerated - but encouraged, exactly because it's hard to tell if someone is just bullshitting around in the five minutes you look at the article or nay. A bit of instinct, I find, seems neccessary. I go almost entirely by instinct. For example, if I find the article is being vague or oddly formulated, I avoid linking to it. Beyond that, I do it with childish glee and passion.
*giggle*