An idea/suggestion for discussion:
There are some mats that are hard to come by. We could have a once-a-month mat run. One day we go after as much felcloth as we can gather, and dump all of it in the guild vault for members to buy. The next might be dragon scales, or whatever. We'll have to come up with a list, targeted towards mats that are hard to get, in high demand and which will directly benefit the most guild members, either through acquiring skill levels, or to make items for members.
With 5 60-70 level characters, most of these runs would probably take longer just gettting to the target area than it would wiping out all the monsters. We could hopscotch to several areas in a row and be done in a half hour.
Whaddya think?