Android: Running an Android phone and want to track your usage? CallTrack plots all your calls, or just particular calls, on a Google Calendar of your choosing.
The app itself consists of nothing more than a few settings, to choose which types of calls (incoming, outgoing, or missed) should be recorded, and which calendar to write to. I set up a new calendar ("Calls," because I'm creative), then headed to the Calendar app and made sure it was selected in the My Calendars settings. From then on, CallTrack could record my calls to that calendar, and I could dump my existing call log into the calendar, if I had a backlog that I deemed important. Having a day-by-day record of your phone activity, and the length of each call, can certainly help out those tracking their time and expenses for work, and help out anyone who's experiencing an odd memory lapse.
CallTrack is a free download for Android phones.