I hate running out of glue. Now I keep 3-4 bottles on hand. I picked up a nice little 16" toolbox from Home Depot for $6, holds my frag plugs, test kits, glue, etc. All that little stuff that's hard to keep organized just stays in there.
Sorry for the threadjack. With zoas, if you run out of glue, you could always take some sewing thread and tie them LOOSELY to the plug or rock, then cut the line after 2-3 weeks.