While browsing Wikipedia I bumped into this interesting list, Ten things you may not know about Wikipedia (full list with descriptions can be found here). As a frequent user and sometimes contributer I found this quite interesting, especially number 6.

1. We’re not for sale.
2. Everyone can use our work with a few conditions.
3. We speak Banyumasan…and about 250 other languages.
4. You can’t actually change anything in Wikipedia…you can only add to it.
5. We care deeply about the quality of our work.
6. We do not expect you to trust us.
7. We are not alone.
8. We are only collectors.
9. We’re neither a dictatorship nor any other political system.
10. We’re in it for the long haul.

Of course, as with any source, you should always check before accepting anything as truth, doubly so with publicly-editable sources, but I still would actually grade my trust of Wikipedia info as 90%.