Perhaps I am just not skeptical enough, but I have found it to be a useful entry point when researching a new topic. The wikipedia articles usually provide plenty of links to original sources.

I will admit that I don’t use it for current events or particularly controversial topics, mostly being focused on some new area of science or technology I’m interested in.

This page on SpaceX is a good example:

http://en.wikipedia.org/wiki/SpaceX

As of today (1/8/2013) it has 94 external sources cited, including the original COTS contract between SpaceX and NASA:

http://www.nasa.gov/centers/johnson/pdf/189228main_setc_nnj06ta26a.pdf

If you’re really interested in what the Wiki article writers thoughts were you can also read the talk page:

http://en.wikipedia.org/wiki/Talk:SpaceX

It isn’t so much that object to a crowd-sourced encyclopedia as I treat it with a great amount of skepticism. I have found Wikipedia, the most well known, to be exceedingly unreliable, especially in areas where there is political controversy.

I also find it better to go to original sources for my information, which is another reason I do not trust Wikipedia. The rare times I have used it I have found that it provides no direct links to anything outside of Wikipedia itself. I would trust it more if the articles there instead included direct links to their sources.

Or just using it as a discovery mechanism for new knowledge?