Is that 17 seconds per block globally, or per client? If it's global, how long would the average client take to generate a block? If it's going to take hours t

Is that 17 seconds per block globally, or per client? If it's global, how long would the average client take to generate a block? If it's going to take hours to generate a block, I'm worried that it's going to take forever for an app to generate enough ether to get anything done; buying the stuff using real money is a nonstarter for most applications, so generating it on demand is the only real option.