I use TaskTrack:

http://www.bushsoftware.com/TaskTrack/TaskTrack.html

no setup required, and it tracks exactly how long you spend on each document during the day; so all you have to do is group the documents into tasks and you have the total time spent.

its actually made this stuff a heap easier than it was for me, I never used to bother until the end of the week, now I still dont, but the numbers are right :)

Sounds like a nice app, sort of like RescueTime.

Echoing on what @mkuhn said, i would normally like to use a stopwatch mode when i would be doing something for a long period of time. For example, half a day's work for project A and then switching to project B or something like that.

Otherwise, i tend to just use time slots and fill then in at the end of the day in a spreadsheet. Mechanical and tedious, but it does the job. Of course, it doesn't really help unless i remember to fill the information in.

For me its something I normaly do at the end of my workday. Fiddling with a stopwatch mode throughout the whole day would be somewhat to much effort for me.

Thanks for the feedback!

Presumably this is for http://www.minuteglass.com/? If you are after any significantly large sample data to base some usability/design decisions on, I'd recommend Amazon Mechanical Turk.

Yes, I'm the designer behind Minuteglass and I'll think about using the Mechanical Turk to get some feedback.

Thanks.

I've just been keeping a time log for the past few days. I'm not sure how long I will keep doing it, but right now it works so I just my cell phone for the time, and a piece of paper to write down what I'm doing throughout the day.