UI for something like this is a piece of cake with Qt (esp. upcoming Qt 4.6). Who won't somebody do it as a finger excercise?

The program would be worth more if it synced with something like rememberthemilk; you could probably steal the protocol code from "remember the milk plasmoid".

If you forget online sync, a simple app like this would be around one day of work without esoteric topics to tackle - just use QListWidget and stacked windows.