one of a kind awesomness!!
LittleBigPlanet is based on "Create.Play.Share" concept. You can create your own level using an easy-to-use tools that are supported by beautiful tutorials which will take you step-by-step through almost all tools. You also can play what other players created, then evaluate their work or maybe leaving a comment on why you liked/disliked a their level. Finally you can share levels, which means that you can publish you levels and make them available for other players to play. Of course they'll be able to evaluate your levels and leave comments.
LittleBigPlanet didn't come to the consoles to be like any other game, they came to make a new genre of games that will get people to love it. They did a great job. I can't wait to see what Sony will come up with next. It is a must have for everyone, even if you think you are too old for it.