When setting up a task within the system, you get the option to have the system send you that all important reminder. This reminder can be sent either via Email or SMS, this means if you have a smartphone, the reminder can simply be emailed to you. If you don't have a phone that you pick your emails up on, you can simply tick the box to set-up an SMS alert, this will send you a little message about the task before it is due. However, if you don't have SMS credits, the alert won't be able to send.
To set this, you can go to 'Add a Task' page and select the option for SMS reminders.