I'm starting to get a decent collection of tools! Advice for projects?

[Corvin]

You know what's a lot cheaper than a wood fence if you put it in your self...invisible fence. So, if you only need the fence for the dog and not for privacy, invisible fences are great. The only tool you need is a shovel.

I've always wondered, what happens if the dog is chasing something across the yard? It gets up to speed, gets zapped by the fence as it goes through the "invisible fence" but doesn't have time to stop. Now your dog is stuck on the other side of the fence and can't come home because of the fence.