It's not a novel idea, and it has been in my mind for years: there is a special set of URLs that define what I call my "personal slice of the web". These are the sites that form my blogroll, the feeds I'm subscribed to, the links I tag using del.icio.us, the URLs included in my browser history, etc.
For each one of us, this "personal slice of the web" is much more important and much more familiar than the rest of the web. I have always thought that we should have better tools to manage this "slice". We should be able to view and visualize it better, search it, share it, etc.
During the last couple of days I have been fooling arround with Google Custom Search Engine. A wordpress plugin that creates a CSE using your blogroll is almost ready, it just needs some polishing (you can see it here in action).
I have also written some code to create a Google CSE based on my del.icio.us links (a demo is here) but this needs more work -it's just a couple of quick'n'dirty scripts.