If you're taking the family to the Lafayette region, one local attraction to consider is the Lafayette Natural History Museum, which includes a planetarium and various nature exhibits.  There is also a historic village called Vermilionville http://www.vermilionville.org/  where actors in 19th century costume will take visitors back in time to the early history of the Louisiana territory and teach people more about cajun and creole culture.   Acadian music and other cultural presentations can also be sometimes found at the Acadiana Center for the Arts, http://www.acadianaartscouncil.org/ 

There is also a part of the Jean Lafitte National Historic Park, the Acadian Culture Center, located in Lafayette. It is named after Jean Lafitte, the famed pirate who played an important role in helping the U.S. win the Battle of New Orleans and keep the city in its possession during the War of 1812 against the British.  http://www.nps.gov/jela/index.htm  . The park service facility in Lafayette focuses largely on Acadian culture.   

    Through December 2007, celebrate the 250th anniversary of the birthday of the Marquis de La Fayette, French hero of the American Revolutionary War and namesake of Lafayette.

     The kids may also enjoy a visit to Kart Ranch, which bills itself as "The entertainment capital of Acadiana." http://www.kartranch.com/  This site features go-karts, video games, bumper boats, and more. 
     Finally, visitors to Lafayette often end up stopping at Lake Charles, about an hour and a half west of Lafayette. This is one of the state's most popular outdoor playgrounds and a major tourist attraction in its own right, with beaches, boating, swimming, and much more. http://www.visitlakecharles.org/   As is the case with Lafayette, this is also a stronghold of Cajun culture.