I have been working on a customized Google Search Engine that only indexes sites related toand also other sites that add value in the personal development and motivation areas.
Please check this out and let me know what you think. It is work in progress so please be nice :-). I am adding sites to the index right now and I will be opening a public submission page for you to submit your GTD or productivity site and I will strictly police this to ensure that we can all use it as a tool to make it easier to find some GTD information when we need it.
The AJAX API looks cool and that is my next task as long as this is well received.