1. Spending a copious amount of time (that can usually be spent doing something that is generally considered more productive) browsing and learning odd bits of trivia from www.wikipedia.org. *Wikiing can also be used if you are referring to adding a new Wikipedia entry or modifying a current one.
2. While www.wikipedia.org is the website that originated the word, wikiing can also be used if a user is utilizing other web-based wikis.
I've been wikiing all night long and now I'm going to screw myself over on my big test tomorrow.
I am so good at wikiing. I've made more entries than anyone ever.