Most people are familiar with the word game Free Rice that donates rice to the poor for every correct response to word games. Sleedo is using a similar model to raise revenue for rice donations. Sleedo is a search engine (using the Google custom search service) that donates money to the World Food Programme when people do their Internet searches through Sleedo.
Applications for Education
If you're looking for a way for your students to help a good cause in the course of an Internet search exercise, consider directing them to Sleedo.
Here are some related items that may be of interest to you:
How Web Search Works
Real-Time Search Options
Lesson Plans for Teaching Web Search Strategies