Is there a way to access (2) or more modules when creating a report?

Is there a way to access (2) or more modules when creating a report?

I am trying to create a weekly activity report for sales reps which would need to include information from both the calls and meetings modules.

As of now, I have not been able to figure out if this is possible as the create report function only appears to allow a single child module.  Note...there is a chance I would want to include a third module down the line as the report starts to take shape.

Is there a way to mine data from different modules into one central report?  I am concerned that there is not, as some similar fields have different names in each module.