Not a good idea. Pneumatic tires were one of the biggest advances that propelled cycling (and cars) forward when they were invented in the early 1900's. The lower weight, increased comfort, increased efficiency allowed people to ride further/faster/longer/better than ever before and no one has looked back since. Nowadays, these things are used on cheap, low end children's bikes.

There is also a consensus that these types of tires are on suitable for cheap children's bikes from wal mart. For any type of serious riding, they provide little to no cushioning effect and rims take a hard beating and have a tendency to fail.