Fencing
For events run off-leash, like coursing and agility, one problem is how to fence an area safely - for the dogs and the site and for the people who have to haul the stuff around.
Best option: site with built-in fencing
Snow-fencing, not very period, but fairly portable. (perhaps not in construction orange?)
[[1]] File:Http://www.incord.com/images/barrier-nets/p360k-polyester-barrier-net.jpg [[2]]
Fabric panels?
Other ideas?