I think Kelly's done a great job of defining the key requirements of a good GTD list manager. She proposes several key features to look for:
The timing couldn't be better for me, as I'm in the process of doing a market analysis and writing copy for eProductivity for Lotus Notes, my own GTD implementation tool for Lotus Notes. I think Kelly's list serves as a good foundation of the core features that any sound GTD implementation tool, whether low-tech (e.g. paper) or high tech (e.g. Lotus Notes) should offer.
- Sorting lists by context
- Ability to assign a due date
- Portable for on the go access
- Easily accessible
- More attractive to you than repelling
- Doesn't force priority codes
- Place to capture additional notes
- Ability to search and sort in various ways.
- Robust enough to handle all of your stuff.
If you have not read Kelly's excellent blog post, I encourage you to read it: What makes a good GTD List Manager?
In addition to my own criteria, I plan to run vanilla Notes and eProductivity for Lotus Notes through Kelly criteria and see how they fare. Might make for an interesting discussion. I'll blog my thoughts over on NotesOnProductivity.