One thing missing from Google’s vast array of applications was a “To-Do” application. Now, it's available in Gmail via the third-party application “Remember the Milk."
“Remember the Milk” is a simple, free, online productivity task management tool where you can add tasks to remind you the date on which they must be completed. This was one application many Gmail users asked for and finally got via the Gmail Labs feature, “Add any gadget by URL."
You can now add the “Remember the Milk” gadget by completing the following steps. Before you do the steps however, you should either have an account in "Remember the Milk" or go to their site to set one up first.
1. Log-on to your Gmail account
2. Click “Settings” and Click “Labs”
3. Enable “Add any gadget by URL”
Using add any gadget option, you can add the task management tool 'Remember the Milk'.
4. Click “Save” at the bottom of the page
5. Click “Gadgets” tab at the top portion of the page
6. Copy this URL “http://www.rememberthemilk.com/services/modules/gmail/rtm.xml and paste it in “Add the gadget by its URL.
7. Go to Inbox and enter your "Remember the Milk" username and password, and you will see the tasks in the small window in the left hand side of Gmail.
You can thus add tasks easily in Gmail. You can also manage your tasks in a tiny window, allowing you to postpone or complete activities in just a few steps.
This is a great feature to have in Gmail.