bill - 2:59 am on Apr 22, 2009 (gmt 0)

Sorry, I don't have a comprehensive list like that. However, just about every package I know from MovableType to WordPress can ping when publishing new content. Either it's a built-in function or something you can add.

I think you're misunderstanding the whole reader/aggegrator situation. A lot of these programs are offline programs. When the user turns them on they go out and scan the feeds they're subscribed to. You don't ping them, they scan your feed for updates. The frequency of the updates is dependent on the software.

You can notify multiple services of the availability of new content on your site by pinging, but that doesn't mean reader/aggregator software will automatically be updated.

If you're concerned about notifying Google they have a FAQ here about their pinging policy: Google Blog Search Pinging Service [google.com]