for what it is wikipedia is amazing imo
you can look up pretty much anything and get a rundown. the amount of things i've learned from there is staggering. it should absolutely be banned from being used as a source for study because it just isn't, but it isn't meant to be that.
personally if i was marking uni papers and someone used wiki as a reference page i would treat it the same as if someone cited 'something i heard in the pub'
i absolutely love it tho, for example last few months i have been interested in ancient gods and i have spent all my breaks reading up about egyptian, roman, zoroastrian etc gods on wiki. it isn't the same as reading a book about them of course, but thanks to wiki i have a rough idea what loads of them are called and what they did

I second that! No way should this site be used in an academic paper but wow, is it great to have around for easy reference. I have probably spent hours in the past few years just exploring so many incredibly interesting things. I remember the days of Encarta. That site just wasn't as good, plus I don't think I should have to pay for knowledge.
I have also heard of some less than scrupulous individuals who take advantage of Wikipedia's free-for-all editing functions by engaging in juvenile antics. Such as, say...going to the Obama guy's entry and changing every instance of his surname to "Osama"... but the over-zealous little editors whose lives revolve around the page they edit soon emerge from their slumber to correct these things and restore balance to the universe, so no harm done keeping them on their toes a wee bit, aye.