GNU Parallel is a perl script to help you create shell scripts for task level parallelization. This is at the task level so it's comparable to Condor rather than MPI or OpenMP. It's designed to let you replace shell scripts that operated sequentially with a command that operates in parallel. By default, it forks off as many processes as you have CPU cores but this is adjustable.

I needed to convert FLAC files to MP3 files for my portable player. This was simple to do with the parallel command which is itself a Perl script.

The parallel manual is large and has a lot of examples already. However, I figure a few more couldn't hurt.

I used this shell script to run parallel on all of my flac files and then I had a simple shell script that accepts a path and runs metaflac and lame on it.

$ find -s -L src -type f -name "*.flac" > xlist
$ parallel ./do_convert.sh '{1}' :::: xlist

You can run kill -SIGUSR2 <parallel PID> to toggle the progress display. By default, it doesn't print anything which it executes. Parallel can handle distributing tasks to multiple computers. If you are regularly distributing tasks to multiple computers, you are probably better off with something like Condor which is designed for that. I see parallel as being nice for quick and dirty tasks where you want to run it in parallel without much fuss.