To improve XKCD, you only have to give the following links to your friends or post them in your blog. Each different click will improve XKCD!
Increase population http://xkcd.myminicity.com
So far our population is small so let's get to work clicking that link.
Each person that hits the link, post something else to explain how the city is or what benefit you had. As other options become available, post them as well. Otherwise this is just link spam. So yeah.