I have a few domains hosted on nameservers at Zerigo. Zerigo have 5 nameservers and I have all 5 in the nameserver records for my domains. The nameservers are in different geographical locations (3 in the US, one in London, and one in Amsterdam).
When someone goes to a domain of mine and the DNS resolution occurs, how will it choose a nameserver? Will it always go to the nearest geographical one? Will it go to the one with fewest hops? Will it just choose one at random? (This is assuming all 5 are functioning perfectly).
And does it make any difference which order I list the nameservers in on the domain name records?