Three Worlds Collide is a web novella by Eliezer Yudkowsky of the semi-firm SF variety. As previously mentioned, it is a First Contact story - it deals with the ethics and tactics associated with meeting Starfish Aliens, among other things. To some extent it also reads like a thought experiment about game theory (it was, after all, written for a blog about human rationality). Has many allusions to modern Internet memes and current ideas in the transhumanism community. Also, swearing, Naughty Tentacles, and other stuff which your boss might not like.