If you're the noncommittal sort of LittleBigPlanet fan I am, you've only dug into the included story levels on a hunt for more Sack-person accoutrement, and not dabbled in the wide, scary world of level creation.
MediaMolecule would like you to change that. They're now running a tutorial video over at their official blog, in which several of the team members give you a lengthy tutorial on how to develop your own LBP challenge level. Those are the quickie action stages that spawn off of the regular levels when you find the hidden keys. They're super short and seem to only let you rack up a high score. I've never figured out what they were for, mainly because I can't pick up a new fuzzy winter hat or oversize novelty glasses for my Sack while I'm playing them.
Anyhow, we've swaddled their nice little video in the Official Giant Bomb FancyPlayer for your viewing pleasure. I'm told you can expect more of these videos in the future offering other DIY tips.
Now go forth, children, and create.