Awesome Web Apps: Wikipedia
A list of awesome web apps is not complete without Wikipedia. This encyclopedia that can be edited by anyone is becoming the default place to find information on a vast amount of topics. If Wikipedia was printed, it would contain more than 1000 volumes. Check out this picture which represents what Wikipedia would look like in printed form as of August 2007:
A lot of people have questioned the reliability of an Encyclopedia that anyone, not just "experts", can edit. Surprisingly, the quality of work in Wikipedia is very high. There are always users that spam and vandalize the site, but there are even more users ready to fix these actions. Wikipedia is an excellent example of the power of online collaboration and a very useful application too.