Ask HN: What app(s)/site(s) do you use to help manage your time?

Just wondered what services you use to help manage time? I Have used Toggl a bit which is cool to see how much time I've spent on a project. As far as organising myself goes I use Evernote and I use Instapaper to read things.

I just wondered what other app(s), site(s) help you with time. Either, how they help you organise yourself, save time, make you more efficient etc.

thanks!