Rackspace HQ is is in a former shopping mall outside of San Antonio. Definitely a cool place to tour if you ever get the chance. You can still see where the "stores" were (they're now employee workspaces.)
Less cool place to work. Very, very noisy. Steps were taken to reduce the noise level but it wasn't enough.
Rackspace may be "the original" datacenter for Texas. At least, they're the original data center for the internet age.