Such as calendars, todo apps, freeform "scratch" files, etcetera.<p>Personally I tried Google Calendar for a while and didn't like it. I currently use a plain scratch text file to hold a schedule/todos/etc, but the simplicity actually gets in the way with the schedule, enough that I'm looking for a better solution.
For personal life events Google Calendar.<p>For tracking work related events (decisions, projects etc.) I use my own app Review19 - <a href="http://review19.com" rel="nofollow">http://review19.com</a><p>Have tried a lot of the popular options: Asana, Trello, Pivotal, Google Docs etc. Each has got its own strengths and weaknesses.<p>My colleagues and I are distributed around the world and Review19.com really helps in non traditional tracking such as collaborative decision making.
I use Gmail a lot so what works for me is the app Remember The Milk. On the desktop it loads a task list on the right side of the Gmail screen. I put daily tasks there but for meetings I still take the time to enter it in the google calendar
<a href="http://culturedcode.com/things/" rel="nofollow">http://culturedcode.com/things/</a> and <a href="http://www.streak.com" rel="nofollow">http://www.streak.com</a> for work.<p>Google Calendar for everything.