As for the official Ubuntu one servers I have no idea. However, the repositories (what you refer to as the "Ubuntu" server) is really a system of volunteering mirrors. You can see these mirrors under "Software sources". They are scattered, but quite a few occur at sites of other business.
Ubuntu One server seems to be located in Great Britain as this answer suggests.
And the Ubuntu Main repository, archive.ubuntu.com is also located in the Great Britain. As also this page returns result when input with "archive.ubuntu.com"
Hostname archive.ubuntu.com ISP Canonical Ltd
Continent Europe Flag GB
Country United Kingdom Country Code GB (GBR)
Region Unknown Local time* 03 Jul 2012 05:14
City Unknown Latitude 54
IP Address 91.189.92.183 Longitude -2
Ubuntu One uses Amazon, so the data could be in any one of six locations around the world https://wiki.ubuntu.com/UbuntuOne/TechnicalDetails
As for the official Ubuntu one servers I have no idea. However, the repositories (what you refer to as the "Ubuntu" server) is really a system of volunteering mirrors. You can see these mirrors under "Software sources". They are scattered, but quite a few occur at sites of other business.
Ubuntu One server seems to be located in Great Britain as this answer suggests.
And the Ubuntu Main repository, archive.ubuntu.com is also located in the Great Britain. As also this page returns result when input with "archive.ubuntu.com"
You can also get the result by going to this link