I try to do my part for Wikipedia, although I tend to not really add anything of use to the site besides vandalism reversions and spelling and grammar corrections because everything is already on this ginormomassive (Gigantic + Enormous + Massive) encyclopedia.
I like shiny things.
And I just learned how to actually make a list look like a list on Wikipedia.
I've contemplated the use of my user page as a personal sandbox, but I'm definitely learning stuff from it.
When you make use of Wikipedia's desks (Help desk, Village pump, and the Reference desk), please consider putting some time in as a volunteer by reading and answering some questions at whichever desk you think you will be the most helpful. Remember: the Help desk always needs help, and questions asked at the Reference desk span the breadth of all human knowledge. You're likely to know the answer to some of the questions.