One thing I personally try to do when attending a conference, special meeting or seminar (even if I am not in charge or have anything to do with the details of the meeting) is to watch and see if the speaker is being cared for. I try to notice if he has water, coffee, juice, or whatever, after he speaks. It is amazing how many speakers of major events have nobody to personally see that they are cared for after the main service, meeting, talk or sermon.
Suggestion: Each church fellowship could have one or two men and women who are personally responsible to care for visiting speakers (it might be good to do the same thing for your own pastor!). Make sure that after the service (and between services if there are several services), the visiting speaker knows where the wash room is, has water, coffee, a plate of grapes, cheese and crackers, a granola bar, and so forth, for energy.
A Visiting Speaker Committee should be on hand to welcome the speaker and his family and make sure they are taken care of before, during and after the service with drinks, snacks and even a meal if need be. In other words, practice hospitality. …contributing to the needs of the saints, practicing hospitality (Romans 12:13). Be hospitable to one another without complaint (1 Peter 4:9).