Google started a treasure hunt about a month ago, releasing four questions (one per week) that covered a range of computational topics. I actually joined the treasure hunt late, the 2nd question was already released by the time I got wind of it. The site says there are prizes to be won for the people who are able to provide complete answers first; I'm not sure what my odds of winning anything are since (a) I joined late and (b) I can only do the questions during the weekends, typically a few days after they are released.
Still, for what it's worth, I was able to answer all four questions correctly on the first try. For any programming parts, I wrote up Python scripts to help me through. The problems were pretty good, and also randomly-generated so that you can't just copy the answer from another participant.
Hoping I win something. 😀