Need an application with bugs for testing purposes !! Does anybody know of one?

We are conducting a walk-in recruitment drive for manual testing professionals in our organization. For judging the aptitude of the candidate as regards to testing awareness, I require any sample web-based application (preferably open source). The aim is to make the candidate test the application and see how many bugs he/she can detect. This will show how sharp the candidate is as regards to testing and will also determine his/her oral and written communication skills.

If anybody knows about any such application, please contact me.

Thanks in advance.

Pavan Addanki