Wikipedia's Importance
I have always believed that Wikipedia is our civilization's version of the Great Library of Alexandria or something similar. Search engines and email will have a place in the history books, but I think that the big story will be humanity's attempt to catalog its information in a crowd-sourced manner.
What I Do To Help
We all have our specialties, and I love research. Lately I spend my editing time tracking down reputable information when I search for articles that need citations or references for claims. Making Wikipedia something other than a place to repeat facts that originally were sourced from here is important.
I love genealogy and other research-based hobbies, so helping with the cleanup of the reference material is an important task that I try to do as often as possible.