What kind of activities can I expect to find at a LEGO Kids Fest?
The available activities vary from city to city, but are listed on that city's page under &quot;Fun Activities&quot;. According to the site, they do not vary notably from day to day.

Cleveland, OH (November 4-6)
Hartford, CT, USA (December 2-4)

Some common elements at all the events which are not regular at other Lego attractions are:

Creation Nation - Build your own LEGO creation to add to a huge map of the United States. In the days following the event, come back to the website to see photos of the completed map.
Big Brick Pile - Mix children's imagination with a big pile of brick -- more loose brick than you've seen anywhere else -- and you'll be amazed by the results.
Mystery Mural Build - Join fellow LEGO KidsFest attendees and contribute to a giant piece of LEGO artwork. Assemble a small, color-coded tile of LEGO bricks and add it to the Mystery Mural. As the weekend progresses, the picture develops. In the days following the event, come back to the website to see photos of the final result!

As well as the standard model displays, building areas, race ramps, and store you'll find at Legoland Discovery Centers, Legoland parks, or regular Lego stores.