eProductivity is THE GTD solution for Lotus Notes. It has a very simple and intuitive user interface, one that stays out of the way until you need it. Since the GTD features are so finely integrated into the context of the work you do everyday, you immediately become more productive when using it. eProductivity avoids flashy functionality and complicated routines and instead quietly empowers you to perform your daily tasks faster and more efficiently. This is the hallmark of good software design, something the eProductivity team obviously knows a lot about. For those that want to greatly improve their performance, I can highly recommend eProductivity for Lotus Notes.
Full post: Interface Matters: On Total (e)Productivity In Lotus Notes