Cool open source app for Tasks/Time tracking

I was tasked this morning with finding a way to track my time spent on lots of little customer problems and questions fore detailed billing as well as tracking time on project pases. Yes, microsoft project is a nice tool for that but it's overpriced, designed for a middle manager not a guy in the field to use and simply is a PITA. The solution I found that works nice is at http://www.codeproject.com/tools/todolist2.asp and is customizable to have nice timers to activate when you are working on a task to make time tracking painless.

Best of all It's open source.. so we can modify it if we want to in the future.