I like search hacks by grad students. Like SearchBots, for example.
Searchbots.net is an experimental search engine that investigates the use of mythology, personification and game theory as motivational strategies in creating a sustainable search community. Searchbots has a rich history and is unique in that it allows you to search using more “human” and entertaining types of information like colour and mood. If you picked the colour red you might get a website about tomatoes, communism or angry people.