Like undergraduate, medical school also has its own clubs/associations/interest groups.  These medical school associated clubs may provide a source for clinical/research/community service activities for your medical school application.   Ask if they have any opportunities for undergraduates.  Maybe they are looking for an undergraduate liaison to help them reach out to undergraduates.  Or they need help with putting a large event together and require undergraduates to help since medical students are often more busy studying for their exams.

There are many minority medical student associations (Latino Medical Student Association, Student National Medical Association) that do outreach to get more minority high school and undergraduate students to enter the medical profession.  They may have health fairs and outreach events that undergraduates are often welcomed to help organize and run.

If your undergraduate institution has a medical school associated with it, go and seek out this unique source of activities and experiences.  Be proactive.