PiggyBack
While this is certainly a low entry barrier approach to getting a web site up and running it usually comes with a host of backend problems
Most educational institutions are going to wipe the servers each semester to make room for the next semesters load of students
Volunteer Organizations will have a fluxuating need for the service or the budget to keep the service running so you may loose the host with little or no notice
You also may have limited to no input about what services will be supported on the server
The one exception to this rule is if your volunteer duties include the maintenance of the organizations web site