Repeat after me: "You don't need permission"

If you want to help out, do the following:

• Download modules that you find interesting.
• Review their source.
• If you find any problems or think of new features, contact the author (preferably with some code).
• Give the author adequate time to respond, and email again in a week or so if they haven't responded yet. Do a little asking around in case they're on vacation or something.
• If they still haven't responded release the code on your own.

Don't worry too much about stepping on toes. Any good open source author will take the time to maintain his or her work or pass control on.

Thanks for contributing :)