[oimaz]

can't believe no body talks about ss (socket statistics) - http://www.cyberciti.biz/tips/linux-investigate-sockets-netw.... It crazy fast compared to netstat

[glandium]

And contains more information, too. Before ss, it was close to impossible to know what the other end of a unix socket was for a given connection (except wild guesses from the ids in /proc/pid/fd).