Technical Question

about how google balances load between diff. servers/locations

[Dice]

Hey All,
We've been building a cluster out of what used to be seperate standalone webservers. However we're running into some problems on how to balance and share data/resources over different geographic locations.

I've been wondering about this for a while, hopefully one or several of you guru's can help me solve this question.

How does google geographically balance its load/data over different datacenters?

Do they use round-robin (it would seem silly, but then again, a lot of things coming from google seem silly) or something like akamai does, which I believe is called GSLB, using BGP info from its hosting providers to determine the location of the request and sending the client to the nearest server?

Does anyone here have any specific technical info on this, or hints as to where I can find it, or who I should ask?

Any help will be greatly appreciated!
Regards,
Dice

PS: Also, I would like to apologize in advance if this is not the right place to ask! ;-)