HourDiary does exactly what it claims.
Pros: It is essential we provide professional, fully itemised timesheets & expenses to our many institutional clients. HourDiary has helped us do this and in the process saved many hours of frustration struggling with Excel. I would recommend it to any firm.
Cons: If it could fill in my time sheet for me automatically by scanning my emails, monitoring my phone calls and reading my mind that would be great.