Arctica is just the best volunteering experience on the playa! I love it.
You can also drop in and volunteer any time you want to. They have the Shift Book, and can tell you where the gaps are in the schedule. It's especially fun if you bring some of your campmates along, and do it together as a group.
Black Rock Animal Control and Thunderdome both do this, and it is a BLAST, both for the volunteers and the people in line buying ice.
Anyway, tell them Buckstar Deluxe says hi.