When I started using Google Calendar I wished it had a "To Do List". Well it doesn't but that doesn't mean you can't have one on your Google Calendar. A great Australian site Remember the Milk, what a great name!, allows you to create a To Do list and link it to your Google Calendar.
I have been using it for a few months now and find it works well. Each day in the calendar has a button at the top which will display your tasks for that day. Very handy.
The Remember the Milk site allows you to categorise the tasks, defaluts are work, personal etc. but you can make your own. There is also the option to link a map to a task so you can see where you must be for each task. Very clever. there are some other features I haven't explored yet too.