timesheet helper

I wish there was a simple, no-fuss command line timesheet helper in the spirit of cabal-install and twidge. The kind of interactions I imagine are:

09:00 # timesheet start work draft 3 of the paper
10:00 # timesheet start darcs dwn
10:45 # timesheet start work regression test for ppack
12:00 # timesheet stop
12:30 # timesheet start darcs roadmap
13:15 # timesheet start work regression test for ppack
16:30 # timesheet start darcs patch review
17:00 # timesheet start work meeting
18:30 # timesheet stop

18:30 # timesheet summary
Today 2008-11-07
-------------------
darcs: 2h
work: 6h 30m

18:30 # timesheet details
Today 2008-11-07
-------------------
darcs: 2h
* dwn: 30 m
* roadmap: 45m
* patch review: 45m
work: 6h 30m
* draft 3 of the paper: 1h
* regression test for ppack: 4h
* meeting: 1h 30m

(Note the assumption here that you are never working on two tasks at the same time; clocking in to a new task automatically clocks you out of an old one). The key to this application is simplicity. In its present state, gpe-timesheet (0.32) uses too many confirmation dialogues to be really useful. Loggr is nice and simple, but if I close my browser window, I lose track of things. Another property I would like to have is for the application to be forgiving to mistakes. If it stored timesheets in a simple text format, for example, I could just edit out my mistakes in a text-editor.

For Haskellers, I also wish that we had a common library for writing command line applications with subcommands and switches. This would be useful for darcs, cabal-install, twidge, this timesheet application, and more.