*Wrote the above before I built my own pump track* Now, I would still have to agree to some extent. They need a water source and are a metric butt load of work. However, with the right dirt it does appear that the shape can be retained for longer periods than first anticipated. After visiting Valmont for a second time the amount of work shouldnt matter, the fun factor always comes out on top. i didnt see one person not having fun. A public pump track (that morphs into a skills park) would be awesome to pull off. I wish i had a larger backyard...

Anyway, I posted this to invite you all to my backyard pump track brawl. Saturday Oct 1st after 1pm, Iowa City (PM for address). I have an 'L' shaped pump track and might setup a skinny or two. nothing crazy but it is good fun that easily shows what is possible with a small space and a shovel. This is open to everyone, on any bike, at any level of sobriety. bring your own food/beer.