If you like xargs, but want more flexibility, I'd highly suggest GNU parallel. Such flexibility includes running jobs on multiple computers, running intensive command using all available CPU's (like xargs -P), and creating unique scripts to handle multiple parameters.
Parallel also lets you transparently run stuff on remote servers, automatically handling stuff like copying files back and forth. When I have some heavy ad-hoc data processing to do my new favorite trick is spinning up 50-100 ec2 spot instances, point GNU parallel at them and just fire and forget.
http://www.gnu.org/software/parallel/man.html