Very long time ago, we used to monitor some test OSPF deployments through ethereal. Somehow, we managed to get ethereal to sniff and parse OSPF packets into a text file (I can't recall now, how), which gave us a pretty nice text representation of the OSPF packets seen at the network interfaces. It was then just a matter of patience to grep the relevant parts out of the test file, of course by using Perl.

This is a big and ugly hack, but it worked for us pretty nicely... Also, you can use tcpdump too, but it does not give you so verbose and nicely formatted output...