Some more things that would be useful:
- copy time entry from previous time entry - useful in case you deal with same task several days and would like to copy also comments (and maybe also time period). Could use some modifier key + drag-and-drop to achieve this, for example, in MS Visio, you can use [Ctrl]+drag-and-drop to make copies of existing shapes.
- if I have focus on particular time entry in week view and start typing, it would be nice if the typed in text would be added as comment to time entry (similar to how it works in MS Outlook). And use F2 to edit existing comment.
- if I have overlapping time entries, time entries will overlap also visually in week view and it is impossible to select (with mouse) the time entry at the bottom. One possible solution would be to cycle through all time-entries under mouse cursor upon each click. Another option would be to show overlapping entries side-by-side.