We’re finding all sorts of uses for this now and have moved several websites over to this and have a couple more websites/services (like IRC) scheduled for this.
Purely out of interest I graphed the number of queries per hour through geodns from the two nameservers (one in San Jose, another in Amsterdam) and got:
I was concerned that two VMs wouldn’t work and I’d be looking at needing physical hardware but that hasn’t turned out to be the case yet (barely pushes more than 100Kbps with very little CPU load). Although, since I’ve recently become a VMware DRS fan (like this guy) we’ve already cloned the San Jose nameserver and will be adding that as a third nameserver. Since adding another nameserver/VM splits the load I also think this will scale nicely.