WinPing is free software that can ping any server, and log the response time taken to pinging. You can even run it on an infinite loop, and log all the times. It can then create a graph of the ping times, so that you can easily see the server response time variation over time.
[advt]You just enter either the hostname, or IP address of the server. After that, you can choose what type of ping you want to do. Options that you can customize include Pings on Infinite Loop, setting time between pings, multiple pings together, and more. The best feature of this ping software is the graph that it can generate. It can generate multiple curves on the graph to show various servers that you pinged, and response time for each. This gives a nice analysis about performance of the servers.