[ale] centralized vs separate UPS?

[foobar at stargate.totalchaos.org (Eric Webb)]

And now for something completely different...

I'd like to open a small discussion on your theories for computer room UPS 
systems.  I'd like to see how you would configure a computer room backup
system if you were designing it.  Consider such a computer room to contain
nearly a dozen machines, some at 110V and some at 220V.  This computer room
is not at a corporate HQ, but a regional site which also happens to be the
company's national call center and largest distribution facility.

I guess the biggest thing that I am curious about is would you configure a 
centralized, redundant mass backup system or would you configure each
server with its own UPS?

Can anyone cite examples, possibly including places that they work at?

Thanks,
Eric