Breadth-first search would result in computers exploding due to the size of the database before I could get anywhere with results.
Depth-first search would work better, but may still need to impose a limit on the number of links down it goes.
In other news, it occured to me that podcasts have a very similar format to blogs (in fact, they are blogs, just with the addition of sound files in their feed), so I may need to find some way of dealing with this.
Also, Talkr is a services that turns text-based blogs into podcasts. Looks fairly interesting, but I doubt I’ll ever use it. I read all the blogs I subscribe to quicker than I could listen to them and I already have a hefty menu of podcasts that I listen to regularly.