FriendFeed lets you see a user’s subscriptions but it doesn’t let you see which users are subscribed to that user. For example, you can see who Robert Scoble follows, but you can’t see Scoble’s followers (the list of users subscribed to his feed).

So, I’m thinking maybe I can crawl the public feed, discover users and read their subscriptions. Each subscription will point at other users to discover and so on. Once I get enough data, I can just look at the list of subscriptions from the opposite direction (from the subscribers point of view), meaning I would be able to see which users and how many are subscribed to a user.

This will effectively give an estimate as to the “social weight” of that user, at least among the active and discoverable users of FriendFeed.

Interesting. I’ll get to work on it as soon as I can and share the results.