A month or so ago I raved about Alfred App and how impressed I was with it. I've also been a long time user of Remember The Milk to keep lists of the things I should be doing.
The good folks over at Ruk have shown how to bring these two worlds together using a Ruby command line script. This now means entering a TODO/reminder can be as simple as :
r Mail Jim about bulk purchase rates of hamsters ^Wed 9am
This really helps my flow through the day - things that would have become interruptions can be quickly added to the TODO list without any real context switch.
If you are a Mac user you really owe it to yourself to go try AlfredApp out.