I would like to have Access record a log that list the error message a user sees. Every once in awhile a user comes to me and says, "I got this error message when I tried to open the application." It would be nice that I have something running on the lookout for errors and logs them into a table. This way I can be on top of the error messages and fix them so the user never experiences them again.

The build in error trapping into your code, instead of displaying the error code or message as normal just append to an error table.