I have been using an iphone app called hours tracker lately. It lets me punch in and out by project and I can add the hourly rate for each project. It lets me email a simple spreadsheet summary to myself as well.
Generally, I have been using my own Excel spreadsheet which I start when the project starts. I note how many paid hours I have alotted for each project phase, then I track how much I have worked each day and the activity (example: “prepare presentation sheets” etc.).
I review these spreadsheets when I write a proposal for a similar project in order to have a better estimate on how long certain activities might take.
Now I track the hours with the iphone app and then copy them in my Excel spreadsheet at the end of the day…