Servers are power-hungry and expensive. If not well-maintained, they can be temperamental. And outages can cripple a firm. So why not let someone else far away deal with it? "You trade some flexibility for a whole lot more affordable, efficient solution," said Lanham Napier, CEO of Rackspace Hosting (RAX). His San Antonio-based company offers dedicated server hosting as well as more advanced cloud-computing functions, essentially shared server