If you must bill by the hour ...
Here’s a cool utility that could help you recapture some of that lost time. From the TimeSnapper website:
With TimeSnapper you can play back your week just like a movie. You can play it at any speed you like, and jump in at any time you like.
When it's time to fill out that dreaded timesheet, TimeSnapper is a savior. No need to tear your hair out trying to remember where all the time went.
Via Lifehacker.