I’ve moved most of my personal “PIM stuff” online this weekend. I had been a bit frustrated lately, organizationally and technologically. I had been “living” on my PowerBook, using OS X’s mail client, address book and calendaring program. They’re great, especially as integrated with each other as they are, but they do all live in one place. Between home and work I use at least three different computers (only one of them a Mac), and while on the road I “live” out of my “phone-enabled PDA.” I finally had some free time this afternoon and made the move.
First I saved my calendars from iCal (the application) to iCal (the format) files and imported them into Google Calendar. I also set up others in my family with their own calendars. We can subscribe to each others’ calendars, which means we each keep our own calendar updated and we can all see what everyone’s got planned. Google also has a number of public calendars available for subscription, everything from U.S. Holidays (useful) to UGA’s football schedule (somewhat interesting) to Faith Hill’s tour dates (not at all).
I’ve been forwarding all my mail through Gmail to get rid of SPAM for quite a while, so it was already set up. 
I just needed to export my Address Book to a CSV file so I could import it to Gmail. (It was also a good opportunity to clean out my contact list. Gmail has a habit of adding everyone the contact list, even if I don’t think I’ll ever need to contact them again. I think I deleted somewhere over 100 addresses – most from large distribution lists.)
As far as I’ve found so far, Google Calendar doesn’t have any sort of task list or “to-do” area. I’m not sure what I’ll be using to keep track of items that need to be done but don’t have a specific date or time associated with them. If you’ve got a suggestion – especially one that fits into this sort of online paradigm – please drop it in comments.
Google’s applications work great on my mobile PDA, and I’ve already had most of my browsers’ startup pages set to iGoogle, so no matter where I am I’m just a click away from most of my important info. Now I just need to keep it all up-to-date.
I’ve played with Remember the Milk (http://rememberthemilk.com) a bit but I don’t have many things to put into it. It doesn’t build a to-do list that just shows up on googlecalendar sidebar. So far my to-do method on the calendar has been to make an event with no time. That shows up in a solid bar, pick a calendar (color) that fits the task. That way it can be seen at a glance that there is something to do even weeks in advance.
I just use one of the many todo list gadgets that you can add to the google.com/ig homepage but remember the milk is pretty good. I think it *does* integrate with google calendar though.
Followup to my earlier – it also integrates with Twitter. The Pro service of Milk adds email and/or SMS – but Twitter does that for you no need to add the Pro to a list of expenses.
Try Toodledo, it links up with iGoogle homepage and creates a nice to do list