I have been using RememberTheMilk for a while now but haven't been able to get it to work from a personal project management perspective. I have finally figured out how to do it simply with tags and SmartLists and I love it. Check it out here

http://davfive.wordpress.com/2012/05/14/effective-personal-project-mgmt-with-rtmhow-i-use-rememberthemilk/