I've been using Remember The Milk as a GTD tool and I highly recommend it! Rather than moving your your tasks between notebooks, you move them between lists. The Gears/Chrome client is much faster than the Evernote desktop client, and there is even a Launchy plugin that allows you to insert tasks into RTM quickly straight from Launchy. There are also keyboard shortcuts, which make it even easier. Totally worth the $25 a year to get the iPhone app.
I always thought GTD was neat, but never had the gumption to create a physical filing system. RTM changes that by making GTD much more convenient.