Remember the Milk is a free online task manager that, although not designed specifically as a GTD application, can work well as one. It’s extremely versatile and there are various ways it can be set up.
Your list of tasks are on the left. When you select a task its details are shown in a box on the right. You can add a due date, repeat and time estimation amongst others. You are also able to add keywords which is how I added contexts – @errands, @mac, etc. Notes can also be added.
There are five default lists or tabs when you first start – inbox, personal, study, work and sent. I used lists in place of projects and had my tasks within them. Generally this worked pretty well. A disadvantage is that when a project is completed I couldn’t find a way of archiving it. I think you just have to delete it.
To create a next actions list I marked actions as high priority and created a smart list that only searched for this priority. I don’t really like having to manually mark tasks as next actions but it works okay.
RTM has a lot of impressive extra features. You can email yourself tasks (you are given a special email address to do this). You can be sent reminders via email, instant messaging or text message (although I couldn’t get the text message service to work). You can also send tasks to other people who also have an RTM account. You can sync with Windows Mobile phones or an iPhone. This is a pay-for service though ($25 for 1 year) but you can just view your account for free with a mobile browser. There is Google Maps integration and you can subscribe to calendars. It is also possible to access your account offline with Google Gears and Firefox. I don’t use Firefox so it’s not something I tested. It really is amazing that this is all free (other than the mobile version).
I played around with Remember the Milk for a few days decided it wasn’t for me in the end. It has an awful lot going for it – enormously versatile, loads of features – and it’s free. And it works fairly well with GTD. But I found the interface a little cluttered and I really don’t like webapps. My broadband still goes down sometimes and I would be completely lost without access to my task manager. I know I could use Google Gears but I rarely use Firefox. I prefer Safari and it would irritate me to have to go to another browser just to look at my to-dos. I also found the iPhone webapp really slow.
I would certainly recommend taking a look at Remember the Milk if you haven’t already. It’s free so there’s nothing to lose and it has a lot of really useful features. But for me it can’t beat Things.