I found [this page](http://viget.com/extend/protip-passing-parameters-to-your-rake-tasks) describing rake args that shows how to set defaults (near the bottom), so you could have an argument for which modules, and have a special value for "all" or just have the default be a list of all of them.

I also found [this stackexchange answer](http://stackoverflow.com/questions/12055877/how-can-i-pass-an-array-as-an-argument-to-a-rake-task) which shows a pattern for using a string with spaces for a list in a single argument, and then splitting on the spaces. That would probably be the best thing, with the name of each module you want separated by spaces?