I am not someone who uses VHF/UHF repeaters from home as a rule, but I do have a mobile 2m/70Cms set in my car and have been known to make the odd contact via a repeater when mobile.One of the strangest things I have heard on a repeater was an amateur, clearly operating from home, telling his QSO partner that he refused to speak to mobile stations using the repeater as he thought mobile operation was unsafe! Now of course this may be a reasonable point of view but the irony is that the repeater network was intended for use by mobiles and portables, so really- no mobiles-no reasons for repeaters. I couldn't resist calling into this conversation and making this point, and yes the station in question did speak to me even though I was mobile! I think though my point was lost on him.
When I first became interested in amateur radio it was drummed into me that repeaters were for mobiles and that if fixed stations were using the "box" that they should always give priority to mobile stations. From the repeaters I hear whilst mobile day to day this doesn't always happen. If you are interested in operating procedure and the ethics of amateur radio try this link its a very interesting document. Maybe it should form part of the current exam strucure. What do you think?