How practical is an unicycle on uneven surfaces? From my experience riding a bicycle the fact that a bicycle has two wheels makes it rather easy to ride over minor obstacles like minor cracks in the road. Segway also looks promising in this aspect although it's rider's guide is full of "don't do this [usually refers to trying to ride over an obstacle in wrong way] otherwise your Segway looses grip of the terrain and you fall big time" phrases.

Now a unicycle has only one very tiny spot of contact with the road. How does one ride over obstacles on a unicycle?
If the word "practical" ever enters your vocabulary, then you really have no business messing around with unicycles.

Unicycling over rough terrain can definitely be done, but it ain't easy.