How to approximate geographical location based on network latency?

Question

I'm looking ways to approximate a client's geographical location based on network latency. I have a p2p mesh where I can measure the latency from one peer to all the other peers.

So for example I have:

• target peer at location unknown
• peer1, located at New York, has latency 100ms to target
• peer2, located at UK, has latency 500ms to target
• peer3, located at Japan, has latency 300ms to target
• peer4, located at Mexico, has latency 100ms to target

Neglecting the fact that network latency isn't an accurate measure of time-of-flight, and network routes aren't always straight, how could I approximate target peer's location?

(So in other words, I'd like to assume network latency is a direct measure of distance)

I think this should be an easy task on 2D plane that is not circularly connected, but how to do this on a sphere such as our earth?

Thanks