I tried a similar thing at work several years ago, before "scrum" took hold everywhere. I kept my to-do list as a stack of post-it notes, and when they were done, I'd ball them up and throw them into a decorative glass mug someone left in my office.

"Update ownership on parser tests." "Get M3 feature list from Dan." "Finish code coverage slide deck." "Call dentist." "Buy quicklime and duct tape." "Investigate ia64 hang." "Finish mid-year discussions."