The best sources are normally specific to one network, for example AT&T have a very informative network status page where you can select a US city and see netwo

The best sources are normally specific to one network, for example AT&T have a very informative network status page where you can select a US city and see network performance from it to other cities around the US and the world. http://ipnetwork.bgtmo.ip.att.net/pws/current_network_performance.shtml http://ipnetwork.bgtmo.ip.att.net/pws/current_network_perfor...