I have had my iPhone 3G for just about a week now, and I already have a favorite app. As you might have guessed from the screen shot it's OmniFocus for iPhone. Having your todo list where ever you go is such a huge benefit that I almost can't describe how super nice it is. "OmniFocus on the iPhone":http://www.omnigroup.com/applications/omnifocus/iphone/ completes the circle for me, as it puts "the system" in my pocket, allowing me to capture new tasks when ever I want, where ever I go. For "the system" to work you have to use and trust it 100%, and if it exists solely on your computer, any tasks you create while away from it has to be remembered, written down or otherwise captured outside of the system. This will leave you with the uncertainty of where your tasks exist and a half used system. bq. "Did I transfer this item?" "Didn't I finish this task yesterday?" Having "the system" in your pocket rocks! There is still a lot of room for improvement in both the desktop and the iPhone app, but I still think that OmniFocus is the best Getting Things Done app out there, across all platforms and systems.