Identifying when netblocks have been assigned

[woody at pch.net (Bill Woodcock)]

      On Sat, 13 Sep 2008, Bill Woodcock wrote:
    > By that, I mean that they could be run daily, and specific results emailed 
    > to people who were interested in following the allocation patterns for 
    > specific organizations, any time there was a match.

Following up on my own post for the second time tells me that I'm posting 
too early in the morning, or without the recommended seven-second 
broadcast delay between brain and fingers, but...  My colleagues have 
reminded me that we already built this system two years ago, and it 
produces an RSS feed, rather than email results.  Also, that we hadn't 
done as much as we should do to provide filtering tools to narrow down the 
results.  So, two questions for the community:

    1) Would people prefer to receive these results via email, or RSS, or 
       some other mechanism?

    2) What would the structure of the query or filter look like, ideally?
       What key would you like to be querying on, and how would you like
       the results focused?

                                -Bill