Google Calendar
Well the big news on the street to day is that google has released a calendar to the public. There's been a lot of action on the internet in the last little while with lots of start-up companies developing calendaring webpages on the hope that google would buy it from them.
Well it's out and I don't think it's all that great. The interface is difficult to navigate. You can't add events by clicking the "add event" link – but the "quick add" seems to work. Repeating events (e.g. teach RE every Tuesday) don't work.* Overall it seems to be less functional than hipcal was when it was first released – and it doesn't have a task section, only events. (You can read my thoughts on hipcal from a few months ago here.)
*Edit – It seems that the loss of functionality is due to Norton Internet Security's pop-up blocker. The features are there and do work if you don't use NIS. I'm currently having lots of issues with the pop-up and ad blocker in NIS and recommend turning them off if you are using firefox or another browser that includes these features.
However, if you've got a google account it's worth checking out. And you can easily import/export the data from/to your current calendering application.
I've stopped using online calendars however, as keeping two lists (paper and computer) up to date was not worth the hassle. However if you "can't" keep a paper calendar, or are used to using a computerised calendar, a web based calendar has lots of advantages (you can access it anywhere, get reminders sent to your phone/email etc.)
I am find Remember the Milk very helpful though. Scraps of paper really don't work for a task-list, and an online collection with reminder emails is a great way for me to keep track of what I need to do during the week.