James Cohen has a quick post about what he calls a "poor man's parallelization" for working with batch jobs. It takes in parameters that tell it which set of jobs to run through when looping.

One common problem that I’ve seen time and time again with batch processing jobs (generally cronjobs) is that when they’re written they run quickly. Over time their workload grows until eventually it’s unacceptably slow. [...] To create a simple of way of separating the jobs in a consistent way we can use the modulus operator. It just calculates the remainder of two numbers. It’s a common arithmetic operator in almost all languages so this technique is pretty portable.

His proof-of-concept script takes in two parameters, the starting job number and the number to increment. His example is user IDs, but this type of script could be used for anything with an ID number. The script is then run from the command line with the parameters of your choosing.