When doing my internship at Sinergise I got this little project after two months being there. It involved creating a website that stores illegal dumps in Slovenia based on their GPS location and extra data that users added themselves. Volunteers then cleaned these dumps and marked them clean.
Extra features involved exporting maps to images, importing GPS files, CSV and SHP exporting and checking various statistics based on areas. The project used Geopedia to store and retrieve the data and an extra challenge was to convert the custom database forms into HTML JSP forms and parsing them intuitively. I have created a form generator that generated any form based on the given ID from Geopedia and a specially created servlet was used to parse them and store them back.