You can also find dog agility jumps online at places like amazon... For me as a kid it was the wooden pole that secured the sliding glass door closed, or hula hoops. Also my dog was a willing horse for many years :-)
(A decidedly unhorsey) MrB knocks over a feed bucket at the tack shop and mutters, "Oh crap. I failed the stadium jumping phase."
(he does listen!)
Clothesline poles on chairs or picnic table benches on end. My childhood dog was my junior hunter... For a 30lb dog, she was damn good, too! She could clear the picnic table on end, not just the benches.
Try Jumps West. That's where we got ours, a set of three cute ones. We've lent them out so many times to kids with horsey themed birthday parties in their backyards. They also made a great photo shoot with a bunch of little ones and ponies. The Jack Russell has had quite a career jumping them in the backyard with my kid and the neighborhood kids.
Google "directions for dog agility jumps" and you will get lots of plans for great jumps made out of PVC pipe. I've made quite a few and they are pretty simple to create. Decorate your pvc pipe with stripes of colored electrical tape and you're good to go.
We also bought fancier dog agility jumps (cool standards) for not that much money (if memory serves). Again, just google dog agility jumps.
"Once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return." --Leonardo Da Vinci
I would just make a few "rails" out of PVC pipe and you can stripe them with colored duct tape. They could be set up on just about anything as x-rails or small verticals (you could even paint some cardboard boxes white, etc.) Whatever you put them on the striped rails will make them feel like real jumps.